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<journal-id journal-id-type="publisher-id">Front. Artif. Intell.</journal-id>
<journal-title>Frontiers in Artificial Intelligence</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Artif. Intell.</abbrev-journal-title>
<issn pub-type="epub">2624-8212</issn>
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<publisher-name>Frontiers Media S.A.</publisher-name>
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<article-meta>
<article-id pub-id-type="doi">10.3389/frai.2025.1599799</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Artificial Intelligence</subject>
<subj-group>
<subject>Original Research</subject>
</subj-group>
</subj-group>
</article-categories>
<title-group>
<article-title>CMDMamba: dual-layer Mamba architecture with dual convolutional feed-forward networks for efficient financial time series forecasting</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name><surname>Qin</surname> <given-names>Zhenkai</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
<xref ref-type="author-notes" rid="fn001"><sup>&#x02020;</sup></xref>
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<contrib contrib-type="author">
<name><surname>Wei</surname> <given-names>Baozhong</given-names></name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
<xref ref-type="author-notes" rid="fn002"><sup>&#x02020;</sup></xref>
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<contrib contrib-type="author">
<name><surname>Zhai</surname> <given-names>Yujia</given-names></name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
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<contrib contrib-type="author">
<name><surname>Lin</surname> <given-names>Ziqian</given-names></name>
<xref ref-type="aff" rid="aff5"><sup>5</sup></xref>
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<contrib contrib-type="author">
<name><surname>Yu</surname> <given-names>Xiaochuan</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
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</contrib>
<contrib contrib-type="author" corresp="yes">
<name><surname>Jiang</surname> <given-names>Jingxuan</given-names></name>
<xref ref-type="aff" rid="aff6"><sup>6</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>&#x0002A;</sup></xref>
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<aff id="aff1"><sup>1</sup><institution>Network Security Research Center, Guangxi Police College</institution>, <addr-line>Nanning</addr-line>, <country>China</country></aff>
<aff id="aff2"><sup>2</sup><institution>School of Information Technology, Guangxi Police College</institution>, <addr-line>Nanning</addr-line>, <country>China</country></aff>
<aff id="aff3"><sup>3</sup><institution>School of Computer Science and Artificial Intelligence, Southwest Jiaotong University</institution>, <addr-line>Chengdu</addr-line>, <country>China</country></aff>
<aff id="aff4"><sup>4</sup><institution>Institute of Software, Chinese Academy of Sciences</institution>, <addr-line>Beijing</addr-line>, <country>China</country></aff>
<aff id="aff5"><sup>5</sup><institution>School of Public Administration, Guangxi Police College</institution>, <addr-line>Nanning</addr-line>, <country>China</country></aff>
<aff id="aff6"><sup>6</sup><institution>School of Business Administration, Guangxi Vocational and Technical Institute of Industry</institution>, <addr-line>Nanning, Guangxi</addr-line>, <country>China</country></aff>
<author-notes>
<fn fn-type="edited-by"><p>Edited by: Arianna Agosto, University of Pavia, Italy</p></fn>
<fn fn-type="edited-by"><p>Reviewed by: Pier Giuseppe Giribone, University of Genoa, Italy</p>
<p>Paola Cerchiello, University of Pavia, Italy</p></fn>
<corresp id="c001">&#x0002A;Correspondence: Jingxuan Jiang <email>jjxuan666&#x00040;gmail.com</email></corresp>
<fn fn-type="other" id="fn001"><p>&#x02020;ORCID: Zhenkai Qin <ext-link ext-link-type="uri" xlink:href="https://orcid.org/0009-0002-8862-2439">orcid.org/0009-0002-8862-2439</ext-link></p></fn>
<fn fn-type="other" id="fn002"><p>Baozhong Wei <ext-link ext-link-type="uri" xlink:href="https://orcid.org/0009-0002-4152-8971">orcid.org/0009-0002-4152-8971</ext-link></p></fn></author-notes>
<pub-date pub-type="epub">
<day>15</day>
<month>07</month>
<year>2025</year>
</pub-date>
<pub-date pub-type="collection">
<year>2025</year>
</pub-date>
<volume>8</volume>
<elocation-id>1599799</elocation-id>
<history>
<date date-type="received">
<day>25</day>
<month>03</month>
<year>2025</year>
</date>
<date date-type="accepted">
<day>20</day>
<month>06</month>
<year>2025</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#x000A9; 2025 Qin, Wei, Zhai, Lin, Yu and Jiang.</copyright-statement>
<copyright-year>2025</copyright-year>
<copyright-holder>Qin, Wei, Zhai, Lin, Yu and Jiang</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</p></license>
</permissions>
<abstract>
<sec>
<title>Introduction</title>
<p>Transformer models have demonstrated remarkable performance in financial time series forecasting. However, they suffer from inefficiencies in computational efficiency, high operational costs, and limitations in capturing temporal dependencies.</p></sec>
<sec>
<title>Methods</title>
<p>To address these challenges, we propose the CMDMamba model, which is based on the Mamba architecture of state-space models (SSMs) and achieves near-linear time complexity. This significantly enhances the real-time data processing capability and reduces the deployment costs for risk management systems. The CMDMamba model employs a dual-layer Mamba structure that effectively captures price fluctuations at both the micro- and macrolevels in financial markets and integrates an innovative Dual Convolutional Feedforward Network (DconvFFN) module. This module is able to effectively capture the correlations between multiple variables in financial markets. By doing so, it provides more accurate time series modeling, optimizes algorithmic trading strategies, and facilitates investment portfolio risk warnings.</p></sec>
<sec>
<title>Results</title>
<p>Experiments conducted on four real-world financial datasets demonstrate that CMDMamba achieves a 10.4% improvement in prediction accuracy for multivariate forecasting tasks compared to state-of-the-art models.</p></sec>
<sec>
<title>Discussion</title>
<p>Moreover, CMDMamba excels in both predictive accuracy and computational efficiency, setting a new benchmark in the field of financial time series forecasting.</p></sec></abstract>
<kwd-group>
<kwd>Mamba</kwd>
<kwd>financial time series forecasting</kwd>
<kwd>deep learning</kwd>
<kwd>State Space Models</kwd>
<kwd>computational efficiency</kwd>
</kwd-group>
<counts>
<fig-count count="11"/>
<table-count count="4"/>
<equation-count count="10"/>
<ref-count count="57"/>
<page-count count="18"/>
<word-count count="9848"/>
</counts>
<custom-meta-wrap>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>AI in Finance</meta-value>
</custom-meta>
</custom-meta-wrap>
</article-meta>
</front>
<body>
<sec sec-type="intro" id="s1">
<title>1 Introduction</title>
<p>Financial time series forecasting constitutes a fundamental component of quantitative finance, underlying essential tasks such as algorithmic trading, risk assessment, and portfolio optimization (Liu and Kim, <xref ref-type="bibr" rid="B28">2025</xref>). Accurate and robust predictive models enable market participants to anticipate asset price dynamics, adapt to structural market changes, and design data-driven investment strategies (Salinas et al., <xref ref-type="bibr" rid="B40">2020</xref>). However, financial time series exhibit distinctive complexities absent in conventional domains (e.g., energy demand, traffic flow), including pronounced nonstationarity, high frequencystochastic noise, regime-switching behavior, and evolving cross-asset dependencies driven by macroeconomic indicators, geopolitical shocks, and behavioral factors (Patel and Singh, <xref ref-type="bibr" rid="B37">2023</xref>). These features significantly complicate the modeling process and undermine the effectiveness of traditional time series techniques.Conventional statistical models such as Autoregressive Integrated Moving Average (ARIMA) (Pokou et al., <xref ref-type="bibr" rid="B38">2024</xref>) and Generalized Autoregressive Conditional Heteroskedasticity (GARCH) (Han et al., <xref ref-type="bibr" rid="B18">2024</xref>) have been widely applied in financial forecasting. However, their reliance on linear assumptions and limited capacity to adapt to dynamic structural changes render them inadequate for disentangling meaningful market signals from pervasive noise, especially under high-volatility conditions (Sezer et al., <xref ref-type="bibr" rid="B41">2020</xref>).</p>
<p>To address these limitations, alternative architectures such as Multi-Layer Perceptrons (MLPs) and Temporal Convolutional Networks (TCNs) have been explored. MLP-based models offer advantages in terms of linear computational complexity and robustness to low signal-to-noise ratios, largely attributed to their residual design mechanisms (Zeng et al., <xref ref-type="bibr" rid="B53">2022</xref>). However, they generally lack explicit temporal modeling capabilities and tend to respond inadequately to abrupt time-series fluctuations. In contrast, TCNs utilize dilated causal convolutions to effectively capture long-range dependencies while maintaining temporal causality (Ebrahimpour et al., <xref ref-type="bibr" rid="B7">2011</xref>), making them well-suited for data with periodic or trend-based patterns. Nevertheless, TCNs often struggle with modeling nonlinear dynamics and adapting to external perturbations (Behera et al., <xref ref-type="bibr" rid="B2">2023</xref>; Lara-Ben&#x000ED;tez et al., <xref ref-type="bibr" rid="B25">2020</xref>).</p>
<p>Recent advances in State Space Models (SSMs) (Triantafyllopoulos, <xref ref-type="bibr" rid="B46">2021</xref>; Behrouz et al., <xref ref-type="bibr" rid="B3">2024a</xref>), particularly the Mamba architecture (Gu and Dao, <xref ref-type="bibr" rid="B10">2023</xref>), have introduced a new paradigm in sequence modeling by combining selective state transitions with linear time complexity to effectively capture long-range dependencies and suppress noise. However, when applied to financial time series forecasting, Mamba reveals key limitations: it struggles to model hierarchical intra-sequence structures, making it difficult to distinguish short-term fluctuations from long-term economic patterns, and it lacks mechanisms for capturing complex inter-variable dependencies vital to multivariate financial systems. These shortcomings highlight the need for enhanced architectures that build on Mamba&#x00027;s strengths while incorporating hierarchical feature extraction and variable-wise interaction modeling to improve forecasting performance in volatile and interconnected financial environments.</p>
<p>To bridge these gaps, we propose CMDMamba, a novel architecture tailored for financial time series forecasting. CMDMamba integrates a dual-layer Mamba framework with a hierarchical channel-aware learning mechanism to capture the multi-scale temporal structures intrinsic to financial data. The first Mamba layer is tuned for high responsiveness to short-term fluctuations, enabling precise identification of micro-level movements, while the second layer targets long-term dependencies that reflect underlying structural trends. To further enhance inter-variable interaction modeling, we introduce a Dual Convolutional Feedforward Network (DConvFFN), which preserves temporal locality and strengthens cross-channel information flow. Additionally, a block-wise sequence partitioning strategy is adopted to increase semantic granularity, thereby improving the model&#x00027;s capability in capturing nuanced temporal transitions and enhancing generalization performance. The principal contributions of this study are as follows:</p>
<list list-type="bullet">
<list-item><p>We propose a novel architectural framework that extends state space modeling to the domain of financial time series forecasting. By leveraging the structural advantages of the Mamba architecture, this framework effectively addresses the challenges posed by high volatility and complex feature dependencies inherent in financial data.</p></list-item>
<list-item><p>Extensive experiments conducted on four real-world financial datasets demonstrate that CMDMamba achieves an average improvement of 10.4% in multivariate forecasting accuracy compared to state-of-the-art benchmarks. The model excels under high-noise and high-volatility conditions, highlighting its robustness and practical relevance.</p></list-item>
<list-item><p>The proposed framework achieves superior balance between efficiency and performance, maintaining the computational efficiency advantages of linear complexity while matching or surpassing state-of-the-art Transformer-based models in predictive accuracy.</p></list-item>
</list></sec>
<sec id="s2">
<title>2 Related work</title>
<sec>
<title>2.1 Financial time series forecasting</title>
<p>Significant advances have been witnessed in the financial time series forecasting domain, which are driven by deep learning architectures (Ge et al., <xref ref-type="bibr" rid="B9">2022</xref>; Wu et al., <xref ref-type="bibr" rid="B49">2024</xref>; Torres et al., <xref ref-type="bibr" rid="B45">2021</xref>). Despite the notable advancements achieved by deep learning models such as Transformers and Temporal Convolutional Networks (TCNs) in financial time series forecasting, significant challenges remain in fully capturing the inherent complexity of financial data (Khan and Khan, <xref ref-type="bibr" rid="B21">2024</xref>; Smith and Doe, <xref ref-type="bibr" rid="B43">2024</xref>). For instance, Transformer models suffer from quadratic computational complexity, rendering them inefficient for processing complex financial data. Although TCNs are effective in modeling long-range dependencies, they struggle with capturing nonlinear dynamics and adapting to exogenous shocks. Recently, State Space Models (SSMs) have attracted increasing attention for their strengths in long-sequence modeling (Nguyen and Chen, <xref ref-type="bibr" rid="B35">2025</xref>). However, existing SSMs&#x02013;such as Mamba&#x02013;still fall short in capturing the hierarchical structure and cross-variable interactions that are critical in financial time series (Kumar and Lee, <xref ref-type="bibr" rid="B24">2023</xref>; Zhang and Wang, <xref ref-type="bibr" rid="B54">2024</xref>). These limitations form the theoretical foundation for the development of CMDMamba. However, three fundamental challenges still remain: nonstationary data distributions, ultrahigh-frequency noise contamination, and nonlinear cross-asset dependencies. Traditional linear statistical models and their regularized variants, although maintaining computational efficiency and interpretability through shrinkage techniques, are essentially restricted by their dependence on linear additive assumptions Johnson and Martinez (<xref ref-type="bibr" rid="B20">2023</xref>). This limitation seriously limits their ability to capture the intricate non-linear dynamics that is inherent in financial markets (Luo et al., <xref ref-type="bibr" rid="B33">2021</xref>). Empirical studies have shown that these methods have crucial deficiencies in modeling sudden regime shifts in complex financial situations.</p>
<p>Innovations in deep learning architectures (Zhang and Hua, <xref ref-type="bibr" rid="B55">2025</xref>; Yu et al., <xref ref-type="bibr" rid="B51">2024</xref>) have brought about a profound transformation in the methodological framework for financial prediction. Architecturally, multilayer perceptron (MLP)&#x02014;based systems have improved gradient propagation. They achieve this through stacked fully - connected layers with residual connections, as demonstrated by DeepAR&#x00027;s excellent performance in low&#x02014;frequency return prediction benchmarks (Salinas et al., <xref ref-type="bibr" rid="B40">2020</xref>). Temporal convolutional networks (TCNs) utilize causal and dilated convolution operations to build exponentially expanding temporal receptive fields (Yao et al., <xref ref-type="bibr" rid="B50">2023</xref>). Researchers have achieved significant improvements in high&#x02014;frequency trade signal detection by stacking multi&#x02014;layer convolutional modules, especially in market microstructure analysis (Hao and Gao, <xref ref-type="bibr" rid="B19">2020</xref>). To overcome the quadratic complexity bottleneck in Transformer&#x02014;based sequence processing, optimized solutions incorporating sparse attention mechanisms have been developed. The Informer (Zhou et al., <xref ref-type="bibr" rid="B56">2021</xref>) architecture uses probabilistic sampling strategies. Although this approach greatly reduces computational resource demands, the remaining complexity is still not practical for real&#x02014;world financial systems. Despite the use of enhanced techniques leveraging time&#x02014;frequency domain transformations (such as fast Fourier transforms) (Qin et al., <xref ref-type="bibr" rid="B39">2025</xref>), spectral analysis capabilities are still insufficient when dealing with ultra&#x02014;low&#x02014;frequency signals contaminated by strong noise (Zhou et al., <xref ref-type="bibr" rid="B57">2022</xref>).</p>
<p>Current methodologies continue to exhibit critical deficiencies in modeling dynamic coupling relationships among multivariate series. The dual constraints of computational complexity and prediction accuracy present urgent challenges for real-time deployment, particularly pronounced in high-frequency trading environments, where the synergistic mechanisms between market microstructure noise and macroeconomic policy shocks remain insufficiently resolved (Song et al., <xref ref-type="bibr" rid="B44">2024</xref>; Chomicz-Grabowska and Orlowski, <xref ref-type="bibr" rid="B5">2020</xref>). CMDMamba adopts the Mamba architecture, which ingeniously reduces computational complexity to a linear level. The model also introduces a dual-layer Mamba design, dynamically adjusting the state decay rate according to different sensitivities to microstructure and macroeconomics, thereby effectively weakening noise interference and significantly enhancing overall model performance.</p>
</sec>
<sec>
<title>2.2 Applications of State Space Models</title>
<p>State Space Models (SSMs) (Gu et al., <xref ref-type="bibr" rid="B13">2021a</xref>,<xref ref-type="bibr" rid="B16">d</xref>) have experienced a renaissance in sequential modeling, primarily attributed to the groundbreaking advancements in Structured State Space Sequence Models (S4) (Gu et al., <xref ref-type="bibr" rid="B17">2021e</xref>,<xref ref-type="bibr" rid="B14">b</xref>). The innovative High-Order Polynomial Projection Operators (HiPPO) Gu et al. (<xref ref-type="bibr" rid="B11">2020</xref>) initialization framework established by S4 has created a new paradigm, demonstrating unprecedented capabilities in long-range dependency modeling. Subsequent studies have continuously enhanced computational efficiency while preserving the theoretical foundation of continuous system modeling. Notably, the diagonal parameterized SSMs (S4D) Gu et al. (<xref ref-type="bibr" rid="B12">2022</xref>) and data-dependent SSMs (DSS) have laid crucial groundwork for modern SSM applications across diverse domains (Gu et al., <xref ref-type="bibr" rid="B15">2021c</xref>).</p>
<p>The emergence of the Mamba architecture has catalyzed a paradigm shift in this field, representing a quantum leap in SSM research. This seminal work innovatively incorporates time-varying parameterized state matrices combined with hardware-aware parallel scanning algorithms. This dual innovation achieves linear computational complexity while maintaining global dependency capture capabilities, attaining positional awareness levels comparable to Transformer architectures. Such breakthroughs have precipitated the proliferation of derivative models, finding extensive applications in language modeling, audio processing, computer vision, and temporal sequence analysis. Notwithstanding these advancements, current SSM architectures confront substantial optimization challenges. The S-Mamba (Wang et al., <xref ref-type="bibr" rid="B47">2025</xref>) model, while implementing decoupled modeling through channel-temporal state space tensor decomposition (Feng et al., <xref ref-type="bibr" rid="B8">2022</xref>), theoretically exhibits deficiencies in dynamically representing high-order cross-feature interactions within temporal data. The bidirectional gating mechanism in MambaMixer (Behrouz et al., <xref ref-type="bibr" rid="B4">2024b</xref>), though capable of synchronously capturing inter-sequence and intra-sequence dependencies, suffers from significant information loss during forward-backward feature selection processes. TimeMachine&#x00027;s (Ahamed and Cheng, <xref ref-type="bibr" rid="B1">2024</xref>) quad-scale architecture integrates channel mixing mechanisms, yet its static statistical feature-based policy selector proves inadequate in adapting to distributional drift phenomena inherent in non-stationary time series. The parameter-sharing scheme in Bi-Mamba (Liang et al., <xref ref-type="bibr" rid="B27">2024</xref>) enhances temporal modeling efficiency but introduces bidirectional state coupling interference. Moreover, its reverse scanning mechanism requiring full-sequence input conflicts with the low-latency demands of streaming inference, creating critical deployment barriers that highlight systemic architectural contradictions in balancing temporal correlation and real-time processing.</p>
<p>Despite notable progress, critical scientific challenges remain unresolved: how to develop novel architectures capable of capturing cross-variable correlations, modeling complex nonlinear interactions, and maintaining linear computational complexity. This bottleneck constrains the applicability of the Mamba-series models in complex scenarios such as financial forecasting and industrial IoT. Our proposed DconvFFN module effectively captures these correlations, thereby enhancing the predictive performance of the model.</p>
</sec>
</sec>
<sec sec-type="methods" id="s3">
<title>3 Methodology</title>
<sec>
<title>3.1 Problem definition</title>
<p>Financial time series forecasting is formally defined as follows. Let <inline-formula><mml:math id="M1"><mml:msup><mml:mrow><mml:mrow><mml:mi mathvariant="script">X</mml:mi></mml:mrow></mml:mrow><mml:mrow><mml:mo>*</mml:mo></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>&#x02026;</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo>}</mml:mo></mml:mrow></mml:math></inline-formula> denote a multivariate financial time series, where each observation <inline-formula><mml:math id="M2"><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mo>&#x02208;</mml:mo><mml:msup><mml:mrow><mml:mi>&#x0211D;</mml:mi></mml:mrow><mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msup></mml:math></inline-formula> represents a <italic>d</italic>-dimensional vector of financial variables at time step <italic>t</italic>. Given a fixed-length lookback window <italic>T</italic>, the forecasting task at any time point <italic>t</italic> involves predicting the future &#x003C4;-step sequence <inline-formula><mml:math id="M3"><mml:msub><mml:mrow><mml:mrow><mml:mi mathvariant="script">X</mml:mi></mml:mrow></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>1</mml:mn><mml:mo>:</mml:mo><mml:mi>t</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mi>&#x003C4;</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>&#x02026;</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mi>&#x003C4;</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo>}</mml:mo></mml:mrow></mml:math></inline-formula> based on the historical observations within the window <inline-formula><mml:math id="M4"><mml:msub><mml:mrow><mml:mrow><mml:mi mathvariant="script">X</mml:mi></mml:mrow></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>-</mml:mo><mml:mi>T</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>1</mml:mn><mml:mo>:</mml:mo><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>-</mml:mo><mml:mi>T</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>-</mml:mo><mml:mi>T</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>&#x02026;</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>x</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo>}</mml:mo></mml:mrow></mml:math></inline-formula>. This formulation captures the temporal dependencies and multivariate interactions inherent in financial data, enabling the prediction of future trends and patterns.</p>
</sec>
<sec>
<title>3.2 State Space Models</title>
<p>State Space Models (SSMs) describe recurrent processes through latent states <bold>h</bold>(<italic>t</italic>) &#x02208; &#x0211D;<sup><italic>N</italic></sup> governed by a first-order differential equation. Inputs <bold>x</bold>(<italic>t</italic>) &#x02208; &#x0211D;<sup><italic>D</italic></sup> drive state evolution, while outputs <bold>y</bold>(<italic>t</italic>) &#x02208; &#x0211D;<sup><italic>M</italic></sup> are generated via a mapping from <bold>h</bold>(<italic>t</italic>). The dynamic process is illustrated in <xref ref-type="disp-formula" rid="E1">Equation 1</xref>:</p>
<disp-formula id="E1"><label>(1)</label><mml:math id="M5"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:msup><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>&#x0002B;</mml:mo><mml:mstyle mathvariant="bold"><mml:mtext>B</mml:mtext></mml:mstyle><mml:mstyle mathvariant="bold"><mml:mtext>x</mml:mtext></mml:mstyle><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mstyle mathvariant="bold"><mml:mtext>y</mml:mtext></mml:mstyle><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:mstyle mathvariant="bold"><mml:mtext>C</mml:mtext></mml:mstyle><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>where <bold>A</bold> &#x02208; &#x0211D;<sup><italic>N</italic>&#x000D7;<italic>N</italic></sup> denotes the state transition matrix governing temporal dynamics, <bold>B</bold> &#x02208; &#x0211D;<sup><italic>N</italic>&#x000D7;<italic>D</italic></sup> the input projection matrix, and <bold>C</bold> &#x02208; &#x0211D;<sup><italic>M</italic>&#x000D7;<italic>N</italic></sup> the output projection matrix. All three matrices are learnable parameters optimized during training. By employing zero-order hold (ZOH) techniques, the SSM can be discretized, as shown in <xref ref-type="disp-formula" rid="E2">Equations 2</xref>:</p>
<disp-formula id="E2"><label>(2)</label><mml:math id="M6"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:msub><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover><mml:msub><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>B</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover><mml:msub><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>x</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>y</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mstyle mathvariant="bold"><mml:mtext>C</mml:mtext></mml:mstyle><mml:msub><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>h</mml:mtext></mml:mstyle></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>where the state matrix <inline-formula><mml:math id="M7"><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover></mml:math></inline-formula> and input matrix <inline-formula><mml:math id="M8"><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>B</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover></mml:math></inline-formula> are derived from continuous parameters (<bold>A</bold>, <bold>B</bold>, &#x00394;<italic>t</italic>) through a discretization method. The specific transformation formulas (<xref ref-type="disp-formula" rid="E3">Equation 3</xref>) are given as follows:</p>
<disp-formula id="E3"><label>(3)</label><mml:math id="M9"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover><mml:mo>=</mml:mo><mml:mo class="qopname">exp</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mo>&#x00394;</mml:mo><mml:mi>t</mml:mi><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mover accent="false" class="mml-overline"><mml:mrow><mml:mstyle mathvariant="bold"><mml:mtext>B</mml:mtext></mml:mstyle></mml:mrow><mml:mo accent="true">&#x000AF;</mml:mo></mml:mover><mml:mo>=</mml:mo><mml:msup><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mo>&#x00394;</mml:mo><mml:mi>t</mml:mi><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mo class="qopname">exp</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mo>&#x00394;</mml:mo><mml:mi>t</mml:mi><mml:mstyle mathvariant="bold"><mml:mtext>A</mml:mtext></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>-</mml:mo><mml:mstyle mathvariant="bold"><mml:mtext>I</mml:mtext></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>&#x000B7;</mml:mo><mml:mo>&#x00394;</mml:mo><mml:mi>t</mml:mi><mml:mstyle mathvariant="bold"><mml:mtext>B</mml:mtext></mml:mstyle></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>Where the invertibility of &#x00394;<italic>t</italic><bold>A</bold> enables efficient discretization through linear recurrence operations, the Structured State Space model (S4) introduces HiPPO-initialized constraints on matrix <bold>A</bold>. This integration establishes S4 as a computationally efficient hybrid architecture that combines classical state-space formulations with deep learning principles, achieving superior long-range sequence modeling capabilities compared to conventional recurrent networks.</p>
<p>Mamba innovatively employs a data-driven approach to parameterize critical matrices while integrating a dynamic selection mechanism into the S4 architecture. As illustrated in <xref ref-type="fig" rid="F1">Figure 1</xref>, the proposed hardware-aware parallel algorithm significantly enhances training efficiency. In contrast to self-attention-based Transformer models, this architecture achieves linear computational complexity while preserving global receptive fields. This breakthrough enables the model to efficiently capture long-range dependencies in time series forecasting without incurring the high computational costs associated with conventional methods, thus achieving an optimal balance between computational efficiency and temporal modeling capability.</p>
<fig id="F1" position="float">
<label>Figure 1</label>
<caption><p>Mamba and Transformer Modeling Process Diagram, where the <bold>left</bold> figure illustrates the modeling process of Mamba, and the <bold>right</bold> figure illustrates the modeling process of Transformer.</p></caption>
<alt-text>Diagram comparing Mamba and Transformer architectures. Mamba uses sequential SSM modules connected in a linear fashion. Transformer has layers labeled H0 to HN-1, with inputs and outputs connected to these layers, illustrating different processing methods.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0001.tif"/>
</fig>
</sec>
<sec>
<title>3.3 Model architecture</title>
<p>The architecture of the CMDMamba model, as illustrated in <xref ref-type="fig" rid="F2">Figure 2</xref>, comprises four critical processing stages: Initially, the embedding layer divides the input time-series data into feature blocks with high information density. Subsequently, the DconvFFN module models local correlations among features to achieve dynamic fusion of multi-feature representations. Then, a dual cascaded Mamba processing module is designed, where the high-sensitivity Mamba block captures microscopic fluctuation characteristics within sequences, while the low-sensitivity Mamba block focuses on modeling long-term dependencies across time steps. Finally, the TNF Encoding module blends information from the Mamba-processed temporal features, generating a final feature vector with robust representational capabilities.</p>
<fig id="F2" position="float">
<label>Figure 2</label>
<caption><p>CMDMamba consists of four modules: the Channel Linear Layer module, which uses a linear embedding mechanism for variable decoupling, the DconvFFN module for decoupled learning of multi-dimensional features, the Double-Layer Mamba module for capturing short-term fluctuations and long-term dependencies, and the TNF Encoding Layer for enhancing the convergence and training stability of deep networks.</p></caption>
<alt-text>Flowchart illustrating a time series processing model. The input is a time series dataset processed through a channel linear layer, followed by three DconvFFN components with GELU activation. The output feeds into Mamba and R-Mamba layers, connected to linear, ConvlD, and SMM operations, then enters a TNF encoding layer with normalization and feedforward steps, concluding with a projection to yield the output.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0002.tif"/>
</fig>
<sec>
<title>3.3.1 Channel linear layer</title>
<p>The embedding layer of the proposed model is designed to handle multivariate time series input data <italic>X</italic><sub><italic>in</italic></sub>, with its core architecture inspired by the iTransformer (Liu et al., <xref ref-type="bibr" rid="B31">2023a</xref>) framework through the adoption of a variable-disentangled linear embedding mechanism. This design achieves refined modeling of temporal patterns by independently processing chronological features from individual variables. Furthermore, a variable-specific linear embedding layer is established to separately consider each variable&#x00027;s characteristics during encoding. This strategic separation effectively mitigates noise induced by variable mixing while temporally preserving intrinsic sequential relationships, thereby enhancing semantic information representation. Subsequently, the encoded features of each variable are projected into a high-dimensional space through linear transformation, where <italic>D</italic> denotes the embedding dimension, as shown in <xref ref-type="disp-formula" rid="E4">Equation 4</xref>:</p>
<disp-formula id="E4"><label>(4)</label><mml:math id="M10"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>X</mml:mi><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">Linear</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">Batch</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>X</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula></sec>
<sec>
<title>3.3.2 DconvFFN</title>
<p>To enhance the multidimensional feature extraction capability in financial time series forecasting, we innovatively propose the DconvFFN module. Addressing three critical limitations of traditional single-convolutional layers&#x02014;restricted feature representation capacity, inadequate cross-variable dependency modeling, and the trade-off between computational efficiency and performance&#x02014;our module achieves multidimensional feature decoupling learning through synergistic integration of two functionally complementary 1D convolutional layers. Formally, given an input tensor <italic>X</italic> &#x02208; &#x0211D;<sup><italic>B</italic>&#x000D7;<italic>V</italic>&#x000D7;<italic>D</italic></sup> (where <italic>B</italic> denotes batch size, <italic>V</italic> the number of variables, and <italic>D</italic> the feature dimension), the DconvFFN operation is formulated as <xref ref-type="disp-formula" rid="E5">Equation 5</xref>:</p>
<disp-formula id="E5"><label>(5)</label><mml:math id="M11"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mtext>&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;&#x000A0;</mml:mtext><mml:mtext class="textrm" mathvariant="normal">DconvFFN</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>X</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">Dropout</mml:mtext></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>*</mml:mo><mml:mtext class="textrm" mathvariant="normal">GELU</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">Dropout</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>*</mml:mo><mml:mi>X</mml:mi><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>b</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>b</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>The first convolutional layer <inline-formula><mml:math id="M13"><mml:mrow><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>&#x02208;</mml:mo><mml:msup><mml:mrow><mml:mi>&#x0211D;</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>&#x000D7;</mml:mo><mml:mi>V</mml:mi><mml:mo>&#x000D7;</mml:mo><mml:mi>d</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math></inline-formula> operates along the variable dimension with learnable local receptive fields (kernel size <italic>K</italic><sub>1</sub>), performing feature re-encoding for each variable&#x00027;s temporal sequence to generate intermediate representations with expanded dimension <italic>d</italic>. Subsequently, the second convolutional layer <inline-formula><mml:math id="M14"><mml:mrow><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x02208;</mml:mo><mml:msup><mml:mrow><mml:mi>&#x0211D;</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x000D7;</mml:mo><mml:mi>d</mml:mi><mml:mo>&#x000D7;</mml:mo><mml:mi>D</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math></inline-formula> conducts cross-variable aggregation (kernel size <italic>K</italic><sub>2</sub>) in the expanded feature space, employing a dynamic weight-sharing mechanism to capture nonlinear interaction patterns among variables. The coordinated use of dual Dropout layers and GELU activation function ensures model generalization while enabling nonlinear feature information flow with biased filtering.</p></sec>
<sec>
<title>3.3.3 CMDMamba layer</title>
<p>CMDMamba&#x00027;s basic building block is the Double-Layer Mamba module. It employs two parallel Mamba modules with different temporal sensitivities to jointly process sequential data, thereby capturing both short-term fluctuations and long-term dependencies. Consider an input tensor <italic><bold>x</bold></italic> &#x02208; &#x0211D;<sup><italic>B</italic>&#x000D7;<italic>V</italic>&#x000D7;<italic>D</italic></sup> fed into a single Mamba module, where <italic>B</italic> represents the batch size, <italic>V</italic> is the number of variables, and <italic>D</italic> denotes the hidden dimension. The computational process can be divided into three key stages, with the first stage shown in <xref ref-type="disp-formula" rid="E6">Equation 6</xref>:</p>
<disp-formula id="E6"><label>(6)</label><mml:math id="M15"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:msup><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>x</mml:mi></mml:mstyle></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">SiLU</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">Conv1D</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">Linear</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>x</mml:mi></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mstyle mathvariant="bold"><mml:mi>z</mml:mi></mml:mstyle><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">SiLU</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">Linear</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>x</mml:mi></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>The Sigmoid Linear Unit (SiLU) activation, as described in [3] and also known as Swish, introduces non-linearity. The linear transformation Linear(&#x000B7;) projects the input into distinct feature spaces, while the depthwise 1D convolution Conv1D(&#x000B7;) conducts local temporal filtering to enhance the discovery of short-term patterns. This design allows <italic><bold>x</bold></italic>&#x02032;to focus on localized contextual features, while **<italic><bold>z</bold></italic>** retains global signal characteristics, as shown in <xref ref-type="disp-formula" rid="E7">Equation 7</xref>:</p>
<disp-formula id="E7"><label>(7)</label><mml:math id="M16"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:msup><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>y</mml:mi></mml:mstyle></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">Linear</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext class="textrm" mathvariant="normal">SelectiveSSM</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>x</mml:mi></mml:mstyle></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>&#x02297;</mml:mo><mml:mstyle mathvariant="bold"><mml:mi>z</mml:mi></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mstyle mathvariant="bold"><mml:mi>y</mml:mi></mml:mstyle><mml:mo>=</mml:mo><mml:mtext class="textrm" mathvariant="normal">LayerNorm</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:mstyle mathvariant="bold"><mml:mi>y</mml:mi></mml:mstyle></mml:mrow><mml:mrow><mml:mi>&#x02032;</mml:mi></mml:mrow></mml:msup><mml:mo>&#x0002B;</mml:mo><mml:mstyle mathvariant="bold"><mml:mi>x</mml:mi></mml:mstyle></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>The SelectiveSSM(&#x000B7;) implements an input-adaptive state-space model with dynamic parameterization mechanisms. These mechanisms adjust the memory decay rates based on the local context <italic><bold>x</bold></italic>&#x02032;. The element-wise multiplication &#x02297; creates a gating mechanism that selectively combines the temporal dynamics from both branches. The Dual-layer Mamba deploys two parallel Mamba modules with different temporal sensitivities: the high-sensitivity branch focuses on capturing rapid local variations, generating output <italic>Y</italic><sub>1</sub>, while the low-sensitivity branch models the slowly evolving global patterns, producing output <italic>Y</italic><sub>2</sub>. The final output is obtained through feature aggregation, as shown in <xref ref-type="disp-formula" rid="E8">Equation 8</xref>:</p>
<disp-formula id="E8"><label>(8)</label><mml:math id="M17"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mi>Y</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>Y</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>&#x0002B;</mml:mo><mml:msub><mml:mrow><mml:mi>Y</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>.</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>Outputs of the two Mamba blocks, <italic>Y</italic><sub>1</sub> and <italic>Y</italic><sub>2</sub>, are aggregated to yield the final output <italic>Y</italic> of the double-layer Mamba block.</p>
</sec>
</sec>
</sec>
<sec id="s4">
<title>4 Experiment</title>
<sec>
<title>4.1 Datasets</title>
<p>In this experiment, to evaluate the model performance, we selected four publicly available financial time series datasets. These datasets encompass historical trading data from diverse financial markets and were chosen based on their broad applicability and the significant challenges they present in the financial domain. Specifically, these data sets include the German DAX index, the Dow Jones Industrial Average (DJI), the Hang Seng Index (HSI), and Standard &#x00026; Poor&#x00027;s 500 Index (S&#x00026;P500). All data sets cover the period from January 2, 2014, to December 12, 2022, with daily observations collected throughout this timeframe. Each dataset was partitioned into training, validation, and test sets using a 7:1:2 ratio. Detailed characteristics of the data sets are provided in <xref ref-type="table" rid="T1">Table 1</xref>, In addition, <xref ref-type="fig" rid="F3">Figure 3</xref> illustrates the price trends of various variables in each financial dataset over the past two years.</p>
<table-wrap position="float" id="T1">
<label>Table 1</label>
<caption><p>Detailed characteristics of all datasets.</p></caption>
<table frame="box" rules="all">
<thead>
<tr style="background-color:#8f9496;color:#ffffff">
<th valign="top" align="left"><bold>Indicator</bold></th>
<th valign="top" align="left"><bold>Indicator definition</bold></th>
<th valign="top" align="left"><bold>Corresponding characteristics</bold></th>
</tr>
</thead>
<tbody>
<tr>
<td valign="top" align="left">Date</td>
<td valign="top" align="left">Date eRecording day</td>
<td valign="top" align="left">Temporal characteristics</td>
</tr> <tr>
<td valign="top" align="left">High</td>
<td valign="top" align="left">Highest trading price</td>
<td/>
</tr> <tr>
<td valign="top" align="left">Low</td>
<td valign="top" align="left">Lowest trading price</td>
<td/>
</tr> <tr>
<td valign="top" align="left">Open</td>
<td valign="top" align="left">Opening trading price</td>
<td valign="top" align="left">Price type</td>
</tr> <tr>
<td valign="top" align="left">Close</td>
<td valign="top" align="left">Closing trading price</td>
<td/>
</tr> <tr>
<td valign="top" align="left">Adj close</td>
<td valign="top" align="left">Adjusted closing price</td>
<td/>
</tr>
<tr>
<td valign="top" align="left">Volume</td>
<td valign="top" align="left">Total trading volume</td>
<td valign="top" align="left">Active trading</td>
</tr></tbody>
</table>
</table-wrap>
<fig id="F3" position="float">
<label>Figure 3</label>
<caption><p>Descriptive statistics of various features across four different datasets.</p></caption>
<alt-text>Four line charts showing stock indices over time. Top left is DAX, top right is S&#x00026;P500, bottom left is HSI, and bottom right is DJ. Each chart displays open, high, low, close, and adjusted close values marked with different colored points and lines.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0003.tif"/>
</fig>
</sec>
<sec>
<title>4.2 Implementation details</title>
<p>All experiments were conducted using the following configuration: an L2 loss function with Adam optimizer (Kingma and Ba, <xref ref-type="bibr" rid="B22">2014</xref>), initial learning rate of 5 &#x000D7; 10<sup>&#x02212;5</sup>, and batch size of 8. The Transformer-based architecture employed an attention factor of 3, while the Mamba-based model utilized a state expansion factor of 2. Weight decay was consistently set to 0.1 throughout all trials. Training procedures implemented early stopping with a patience period of 10 epochs. To ensure statistical reliability, each experimental condition was independently repeated three times with random initialization. The complete implementation, developed using PyTorch (Paszke et al., <xref ref-type="bibr" rid="B36">2019</xref>), was executed on a dedicated NVIDIA Tesla V100 GPU (32GB memory) (Markidis et al., <xref ref-type="bibr" rid="B34">2018</xref>) to maintain computational consistency across trials.</p>
</sec>
<sec>
<title>4.3 Evaluation indicators</title>
<p>In time series forecasting, the accuracy of the model is crucial for the reliability of decision-making. Mean squared error (MSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) are commonly used evaluation metrics. They can quantify the deviation between the predicted values of the CMDMamba model and the actual observed values from different perspectives, providing intuitive data for evaluating the model&#x00027;s performance. As shown in <xref ref-type="disp-formula" rid="E9">Equation 9</xref>, the calculation is performed as follows:</p>
<disp-formula id="E9"><label>(9)</label><mml:math id="M18"><mml:mtable class="eqnarray" columnalign="left"><mml:mtr><mml:mtd><mml:mtext class="textrm" mathvariant="normal">MSE</mml:mtext><mml:mo>=</mml:mo><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:mfrac><mml:mstyle displaystyle="true"><mml:munderover accentunder="false" accent="false"><mml:mrow><mml:mo>&#x02211;</mml:mo></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:munderover></mml:mstyle><mml:msup><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>&#x00177;</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtext class="textrm" mathvariant="normal">MAE</mml:mtext><mml:mo>=</mml:mo><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:mfrac><mml:mstyle displaystyle="true"><mml:munderover accentunder="false" accent="false"><mml:mrow><mml:mo>&#x02211;</mml:mo></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:munderover></mml:mstyle><mml:mo>|</mml:mo><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>&#x00177;</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>|</mml:mo><mml:mo>,</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtext class="textrm" mathvariant="normal">MAPE</mml:mtext><mml:mo>=</mml:mo><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:mfrac><mml:mstyle displaystyle="true"><mml:munderover accentunder="false" accent="false"><mml:mrow><mml:mo>&#x02211;</mml:mo></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:munderover></mml:mstyle><mml:mo>|</mml:mo><mml:mfrac><mml:mrow><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>&#x00177;</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>y</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>|</mml:mo><mml:mo>&#x000D7;</mml:mo><mml:mn>100</mml:mn><mml:mi>%</mml:mi></mml:mtd></mml:mtr></mml:mtable></mml:math></disp-formula>
<p>In these formulas, <italic>y</italic><sub><italic>i</italic></sub> represents the actual observed value, &#x00177;<sub><italic>i</italic></sub> is the predicted value of the model, and <italic>n</italic> denotes the total number of data points. To accurately compare model performance, we normalize the values. With metrics such as MSE and MAE, we can intuitively assess the prediction accuracy of the CMDMamba model. The lower the values of these two metrics, the closer the predicted values are to the actual values, indicating better prediction performance of the model.</p>
</sec>
<sec>
<title>4.4 Baselines</title>
<p>Since models applicable to general time series forecasting are equally suitable for financial time series prediction, we comprehensively adopt state-of-the-art models from the time series community as baseline references. These include transformer-based models: Autoformer (Wu et al., <xref ref-type="bibr" rid="B48">2021</xref>), Informer Zhou et al. (<xref ref-type="bibr" rid="B56">2021</xref>), Reformer (Kitaev et al., <xref ref-type="bibr" rid="B23">2020</xref>), Pyraformer (Liu et al., <xref ref-type="bibr" rid="B30">2022b</xref>), Crossformer (Liu et al., <xref ref-type="bibr" rid="B32">2023b</xref>), and iTransformer (Li et al., <xref ref-type="bibr" rid="B26">2019</xref>); MLP-based models: TiDE (Das et al., <xref ref-type="bibr" rid="B6">2023</xref>); linear-based models: DLinear (Zeng et al., <xref ref-type="bibr" rid="B52">2023</xref>); convolution-based models: SCINet (Liu et al., <xref ref-type="bibr" rid="B29">2022a</xref>); recurrent-based models: LSTM; Statistical modeling-based methods:GARCH; and Mamba-based models: S_Mamba (Shehzad et al., <xref ref-type="bibr" rid="B42">2020</xref>).</p>
</sec>
<sec>
<title>4.5 Multivariate results</title>
<p>In multivariate predictive analysis, multiple time series are considered simultaneously to evaluate the model&#x00027;s ability to capture interdependencies and mutual influences among various features. The experimental results in four data sets demonstrate that CMDMamba consistently outperforms most baselines and prediction horizon configurations, as shown in <xref ref-type="table" rid="T2">Table 2</xref>. CMDMamba significantly reduced the mean squared error (MSE) by 11. 6% in DAX (0.570 &#x02192; 0.504), 1. 5% in DJI (0.200 &#x02192; 0.197), 0.4% in HSI ( 0.563 &#x02192; 0.561), and 10.2% in S&#x00026;P500 (0.498 &#x02192; 0.447) compared to the previous best results. Compared to the previous best models, the performance of CMDMamba in this configuration improved by 10.4%. As forecast horizons expand, modeling complex long-range dependencies becomes increasingly demanding. In this context, the CMDMamba model distinguishes itself through its exceptional capability to efficiently integrate temporal information and intricate cross-variable dependencies. Its robust performance has been thoroughly validated across multiple real-world datasets, showcasing both outstanding prediction accuracy and broad applicability. However, the performance improvement of CMDMamba on the DJI and HSI datasets is relatively less pronounced compared to other datasets. This may be attributed to the fact that both datasets represent comprehensive stock indices characterized by relatively stable macro trends, rendering their temporal patterns less responsive to the dynamic state transition mechanisms that CMDMamba relies on.</p>
<table-wrap position="float" id="T2">
<label>Table 2</label>
<caption><p>Multivariate forecasting results across four datasets under forecast horizons <italic>O</italic> &#x02208; {12, 36, 58, 96}.</p></caption>
<table frame="box" rules="all">
<thead>
<tr style="background-color:#8f9496;color:#ffffff">
<th valign="top" align="left" colspan="2"><bold>Model</bold></th>
<th valign="top" align="center" colspan="3"><bold>Ours</bold></th>
<th valign="top" align="center" colspan="3"><bold>S_Mamba</bold></th>
<th valign="top" align="center" colspan="3"><bold>iTransformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Film</bold></th>
<th valign="top" align="center" colspan="3"><bold>Autoformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Informer</bold></th>
<th valign="top" align="center" colspan="3"><bold>LSTM</bold></th>
<th valign="top" align="center" colspan="3"><bold>GARCH</bold></th>
</tr>
<tr style="background-color:#8f9496;color:#ffffff">
<td valign="top" align="left" colspan="2" rowspan="2"><bold>Metric</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
</tr> 
</thead>
<tbody>
<tr>
<td valign="top" align="left" rowspan="4">DAX</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.246</bold></td>
<td valign="top" align="center"><bold>0.351</bold></td>
<td valign="top" align="center">1.182</td>
<td valign="top" align="center"><underline>0.283</underline></td>
<td valign="top" align="center"><underline>0.374</underline></td>
<td valign="top" align="center">1.405</td>
<td valign="top" align="center">0.285</td>
<td valign="top" align="center">0.376</td>
<td valign="top" align="center">1.665</td>
<td valign="top" align="center">0.624</td>
<td valign="top" align="center">0.607</td>
<td valign="top" align="center">2.870</td>
<td valign="top" align="center">0.633</td>
<td valign="top" align="center">0.616</td>
<td valign="top" align="center">1.985</td>
<td valign="top" align="center">1.170</td>
<td valign="top" align="center">0.904</td>
<td valign="top" align="center">1.158</td>
<td valign="top" align="center">0.890</td>
<td valign="top" align="center">0.739</td>
<td valign="top" align="center"><underline>1.069</underline></td>
<td valign="top" align="center">1.033</td>
<td valign="top" align="center">0.775</td>
<td valign="top" align="center"><bold>0.991</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.413</bold></td>
<td valign="top" align="center"><bold>0.464</bold></td>
<td valign="top" align="center">1.390</td>
<td valign="top" align="center"><underline>0.459</underline></td>
<td valign="top" align="center"><underline>0.497</underline></td>
<td valign="top" align="center">1.779</td>
<td valign="top" align="center">0.469</td>
<td valign="top" align="center">0.506</td>
<td valign="top" align="center">2.040</td>
<td valign="top" align="center">0.792</td>
<td valign="top" align="center">0.688</td>
<td valign="top" align="center">1.169</td>
<td valign="top" align="center">0.779</td>
<td valign="top" align="center">0.686</td>
<td valign="top" align="center">2.109</td>
<td valign="top" align="center">1.647</td>
<td valign="top" align="center">1.097</td>
<td valign="top" align="center">1.462</td>
<td valign="top" align="center">1.271</td>
<td valign="top" align="center">0.930</td>
<td valign="top" align="center"><underline>1.358</underline></td>
<td valign="top" align="center">1.037</td>
<td valign="top" align="center">0.778</td>
<td valign="top" align="center"><bold>0.994</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.504</bold></td>
<td valign="top" align="center"><bold>0.520</bold></td>
<td valign="top" align="center">1.321</td>
<td valign="top" align="center"><underline>0.570</underline></td>
<td valign="top" align="center"><underline>0.566</underline></td>
<td valign="top" align="center">1.697</td>
<td valign="top" align="center">0.576</td>
<td valign="top" align="center">0.569</td>
<td valign="top" align="center">1.964</td>
<td valign="top" align="center">1.016</td>
<td valign="top" align="center">0.787</td>
<td valign="top" align="center">1.581</td>
<td valign="top" align="center">0.912</td>
<td valign="top" align="center">0.751</td>
<td valign="top" align="center">1.492</td>
<td valign="top" align="center">2.055</td>
<td valign="top" align="center">1.224</td>
<td valign="top" align="center">1.420</td>
<td valign="top" align="center">2.356</td>
<td valign="top" align="center">1.324</td>
<td valign="top" align="center"><underline>1.204</underline></td>
<td valign="top" align="center">1.039</td>
<td valign="top" align="center">0.780</td>
<td valign="top" align="center"><bold>0.996</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.714</bold></td>
<td valign="top" align="center"><bold>0.641</bold></td>
<td valign="top" align="center">1.252</td>
<td valign="top" align="center">0.951</td>
<td valign="top" align="center">0.760</td>
<td valign="top" align="center">1.729</td>
<td valign="top" align="center"><underline>0.931</underline></td>
<td valign="top" align="center"><underline>0.747</underline></td>
<td valign="top" align="center">1.937</td>
<td valign="top" align="center">1.139</td>
<td valign="top" align="center">0.828</td>
<td valign="top" align="center">1.296</td>
<td valign="top" align="center">1.145</td>
<td valign="top" align="center">0.839</td>
<td valign="top" align="center">1.374</td>
<td valign="top" align="center">2.390</td>
<td valign="top" align="center">1.336</td>
<td valign="top" align="center">1.279</td>
<td valign="top" align="center">3.810</td>
<td valign="top" align="center">1.720</td>
<td valign="top" align="center"><underline>1.189</underline></td>
<td valign="top" align="center">1.029</td>
<td valign="top" align="center">0.790</td>
<td valign="top" align="center"><bold>0.992</bold></td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">DJI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.128</bold></td>
<td valign="top" align="center"><bold>0.245</bold></td>
<td valign="top" align="center"><bold>0.385</bold></td>
<td valign="top" align="center">0.138</td>
<td valign="top" align="center">0.258</td>
<td valign="top" align="center">0.396</td>
<td valign="top" align="center"><underline>0.131</underline></td>
<td valign="top" align="center"><underline>0.251</underline></td>
<td valign="top" align="center">0.441</td>
<td valign="top" align="center">0.212</td>
<td valign="top" align="center">0.360</td>
<td valign="top" align="center">0.512</td>
<td valign="top" align="center">0.209</td>
<td valign="top" align="center">0.359</td>
<td valign="top" align="center"><underline>0.394</underline></td>
<td valign="top" align="center">2.871</td>
<td valign="top" align="center">1.561</td>
<td valign="top" align="center">0.592</td>
<td valign="top" align="center">2.046</td>
<td valign="top" align="center">1.311</td>
<td valign="top" align="center">0.705</td>
<td valign="top" align="center">0.968</td>
<td valign="top" align="center">0.825</td>
<td valign="top" align="center">0.993</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.170</bold></td>
<td valign="top" align="center"><bold>0.298</bold></td>
<td valign="top" align="center"><bold>0.389</bold></td>
<td valign="top" align="center">0.188</td>
<td valign="top" align="center">0.319</td>
<td valign="top" align="center">0.455</td>
<td valign="top" align="center"><underline>0.175</underline></td>
<td valign="top" align="center"><underline>0.306</underline></td>
<td valign="top" align="center">0.474</td>
<td valign="top" align="center">0.231</td>
<td valign="top" align="center">0.374</td>
<td valign="top" align="center"><underline>0.411</underline></td>
<td valign="top" align="center">0.265</td>
<td valign="top" align="center">0.413</td>
<td valign="top" align="center">0.471</td>
<td valign="top" align="center">2.657</td>
<td valign="top" align="center">1.510</td>
<td valign="top" align="center">0.635</td>
<td valign="top" align="center">2.825</td>
<td valign="top" align="center">1.551</td>
<td valign="top" align="center">0.778</td>
<td valign="top" align="center">0.966</td>
<td valign="top" align="center">0.822</td>
<td valign="top" align="center">0.995</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.197</bold></td>
<td valign="top" align="center"><bold>0.325</bold></td>
<td valign="top" align="center"><bold>0.382</bold></td>
<td valign="top" align="center">0.214</td>
<td valign="top" align="center">0.348</td>
<td valign="top" align="center">0.493</td>
<td valign="top" align="center"><underline>0.200</underline></td>
<td valign="top" align="center"><underline>0.335</underline></td>
<td valign="top" align="center">0.509</td>
<td valign="top" align="center">0.315</td>
<td valign="top" align="center">0.443</td>
<td valign="top" align="center"><underline>0.467</underline></td>
<td valign="top" align="center">0.319</td>
<td valign="top" align="center">0.456</td>
<td valign="top" align="center">0.539</td>
<td valign="top" align="center">3.183</td>
<td valign="top" align="center">1.650</td>
<td valign="top" align="center">0.627</td>
<td valign="top" align="center">3.080</td>
<td valign="top" align="center">1.622</td>
<td valign="top" align="center">0.834</td>
<td valign="top" align="center">0.965</td>
<td valign="top" align="center">0.821</td>
<td valign="top" align="center">1.002</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.261</bold></td>
<td valign="top" align="center"><bold>0.391</bold></td>
<td valign="top" align="center"><bold>0.448</bold></td>
<td valign="top" align="center">0.284</td>
<td valign="top" align="center">0.415</td>
<td valign="top" align="center">0.591</td>
<td valign="top" align="center"><underline>0.270</underline></td>
<td valign="top" align="center"><underline>0.403</underline></td>
<td valign="top" align="center">0.634</td>
<td valign="top" align="center">0.366</td>
<td valign="top" align="center">0.484</td>
<td valign="top" align="center"><underline>0.473</underline></td>
<td valign="top" align="center">0.409</td>
<td valign="top" align="center">0.522</td>
<td valign="top" align="center">0.609</td>
<td valign="top" align="center">3.326</td>
<td valign="top" align="center">1.691</td>
<td valign="top" align="center">0.727</td>
<td valign="top" align="center">3.471</td>
<td valign="top" align="center">1.721</td>
<td valign="top" align="center">0.825</td>
<td valign="top" align="center">0.953</td>
<td valign="top" align="center">0.812</td>
<td valign="top" align="center">0.999</td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">HSI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.323</bold></td>
<td valign="top" align="center"><bold>0.352</bold></td>
<td valign="top" align="center"><underline>2.153</underline></td>
<td valign="top" align="center"><underline>0.367</underline></td>
<td valign="top" align="center">0.378</td>
<td valign="top" align="center">2.402</td>
<td valign="top" align="center"><underline>0.367</underline></td>
<td valign="top" align="center"><underline>0.372</underline></td>
<td valign="top" align="center">2.232</td>
<td valign="top" align="center">0.782</td>
<td valign="top" align="center">0.701</td>
<td valign="top" align="center">5.570</td>
<td valign="top" align="center">0.622</td>
<td valign="top" align="center">0.604</td>
<td valign="top" align="center">2.388</td>
<td valign="top" align="center">0.557</td>
<td valign="top" align="center">0.513</td>
<td valign="top" align="center">2.388</td>
<td valign="top" align="center">0.520</td>
<td valign="top" align="center">0.474</td>
<td valign="top" align="center">2.956</td>
<td valign="top" align="center">0.997</td>
<td valign="top" align="center">0.799</td>
<td valign="top" align="center"><bold>0.992</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.434</bold></td>
<td valign="top" align="center"><bold>0.449</bold></td>
<td valign="top" align="center"><underline>2.559</underline></td>
<td valign="top" align="center"><underline>0.488</underline></td>
<td valign="top" align="center">0.477</td>
<td valign="top" align="center">3.247</td>
<td valign="top" align="center"><underline>0.488</underline></td>
<td valign="top" align="center"><underline>0.467</underline></td>
<td valign="top" align="center">2.981</td>
<td valign="top" align="center">0.508</td>
<td valign="top" align="center">0.501</td>
<td valign="top" align="center">2.794</td>
<td valign="top" align="center">0.715</td>
<td valign="top" align="center">0.674</td>
<td valign="top" align="center">3.394</td>
<td valign="top" align="center">0.644</td>
<td valign="top" align="center">0.614</td>
<td valign="top" align="center">3.394</td>
<td valign="top" align="center">0.644</td>
<td valign="top" align="center">0.580</td>
<td valign="top" align="center">3.185</td>
<td valign="top" align="center">0.981</td>
<td valign="top" align="center">0.795</td>
<td valign="top" align="center"><bold>0.995</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.561</bold></td>
<td valign="top" align="center"><bold>0.519</bold></td>
<td valign="top" align="center"><underline>2.656</underline></td>
<td valign="top" align="center"><underline>0.563</underline></td>
<td valign="top" align="center"><underline>0.524</underline></td>
<td valign="top" align="center">3.962</td>
<td valign="top" align="center">0.586</td>
<td valign="top" align="center">0.527</td>
<td valign="top" align="center">3.780</td>
<td valign="top" align="center">0.590</td>
<td valign="top" align="center">0.574</td>
<td valign="top" align="center">3.770</td>
<td valign="top" align="center">0.832</td>
<td valign="top" align="center">0.750</td>
<td valign="top" align="center">2.764</td>
<td valign="top" align="center">0.726</td>
<td valign="top" align="center">0.669</td>
<td valign="top" align="center">2.764</td>
<td valign="top" align="center">0.809</td>
<td valign="top" align="center">0.717</td>
<td valign="top" align="center">4.657</td>
<td valign="top" align="center">0.968</td>
<td valign="top" align="center">0.791</td>
<td valign="top" align="center"><bold>1.001</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.695</bold></td>
<td valign="top" align="center"><bold>0.629</bold></td>
<td valign="top" align="center"><underline>5.172</underline></td>
<td valign="top" align="center">0.772</td>
<td valign="top" align="center">0.666</td>
<td valign="top" align="center">5.999</td>
<td valign="top" align="center"><underline>0.765</underline></td>
<td valign="top" align="center"><underline> 0.651</underline></td>
<td valign="top" align="center">5.233</td>
<td valign="top" align="center">0.777</td>
<td valign="top" align="center">0.704</td>
<td valign="top" align="center">5.382</td>
<td valign="top" align="center">1.118</td>
<td valign="top" align="center">0.900</td>
<td valign="top" align="center">5.266</td>
<td valign="top" align="center">0.977</td>
<td valign="top" align="center">0.808</td>
<td valign="top" align="center">5.266</td>
<td valign="top" align="center">1.078</td>
<td valign="top" align="center">0.877</td>
<td valign="top" align="center">5.249</td>
<td valign="top" align="center">0.943</td>
<td valign="top" align="center">0.783</td>
<td valign="top" align="center"><bold>0.998</bold></td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">S&#x00026;P500</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.394</bold></td>
<td valign="top" align="center"><bold>0.292</bold></td>
<td valign="top" align="center"><bold>0.243</bold></td>
<td valign="top" align="center">0.497</td>
<td valign="top" align="center">0.328</td>
<td valign="top" align="center"><underline>0.281</underline></td>
<td valign="top" align="center"><underline>0.491</underline></td>
<td valign="top" align="center"><underline>0.325</underline></td>
<td valign="top" align="center">0.300</td>
<td valign="top" align="center">0.931</td>
<td valign="top" align="center">0.511</td>
<td valign="top" align="center">0.420</td>
<td valign="top" align="center">0.597</td>
<td valign="top" align="center">0.455</td>
<td valign="top" align="center">0.377</td>
<td valign="top" align="center">2.772</td>
<td valign="top" align="center">1.546</td>
<td valign="top" align="center">0.578</td>
<td valign="top" align="center">1.802</td>
<td valign="top" align="center">1.106</td>
<td valign="top" align="center">0.444</td>
<td valign="top" align="center">1.039</td>
<td valign="top" align="center">0.849</td>
<td valign="top" align="center">0.990</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.462</bold></td>
<td valign="top" align="center"><bold>0.352</bold></td>
<td valign="top" align="center">0.229</td>
<td valign="top" align="center">0.532</td>
<td valign="top" align="center">0.364</td>
<td valign="top" align="center"><bold>0.226</bold></td>
<td valign="top" align="center">0.614</td>
<td valign="top" align="center">0.372</td>
<td valign="top" align="center"><underline>0.228</underline></td>
<td valign="top" align="center"><underline>0.463</underline></td>
<td valign="top" align="center"><underline>0.357</underline></td>
<td valign="top" align="center">0.259</td>
<td valign="top" align="center">0.624</td>
<td valign="top" align="center">0.455</td>
<td valign="top" align="center">0.268</td>
<td valign="top" align="center">4.622</td>
<td valign="top" align="center">2.041</td>
<td valign="top" align="center">0.704</td>
<td valign="top" align="center">2.778</td>
<td valign="top" align="center">1.479</td>
<td valign="top" align="center">0.560</td>
<td valign="top" align="center">1.039</td>
<td valign="top" align="center">0.849</td>
<td valign="top" align="center">0.997</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.447</bold></td>
<td valign="top" align="center"><bold>0.343</bold></td>
<td valign="top" align="center"><bold>0.164</bold></td>
<td valign="top" align="center">0.554</td>
<td valign="top" align="center"><underline>0.381</underline></td>
<td valign="top" align="center">0.183</td>
<td valign="top" align="center">0.715</td>
<td valign="top" align="center">0.397</td>
<td valign="top" align="center">0.187</td>
<td valign="top" align="center"><underline>0.498</underline></td>
<td valign="top" align="center">0.391</td>
<td valign="top" align="center"><underline>0.182</underline></td>
<td valign="top" align="center">0.663</td>
<td valign="top" align="center">0.461</td>
<td valign="top" align="center">0.274</td>
<td valign="top" align="center">4.531</td>
<td valign="top" align="center">2.015</td>
<td valign="top" align="center">0.757</td>
<td valign="top" align="center">3.235</td>
<td valign="top" align="center">1.633</td>
<td valign="top" align="center">0.620</td>
<td valign="top" align="center">1.039</td>
<td valign="top" align="center">0.848</td>
<td valign="top" align="center">0.999</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.502</bold></td>
<td valign="top" align="center"><bold>0.399</bold></td>
<td valign="top" align="center"><bold>0.188</bold></td>
<td valign="top" align="center">0.611</td>
<td valign="top" align="center">0.421</td>
<td valign="top" align="center">0.207</td>
<td valign="top" align="center">0.806</td>
<td valign="top" align="center">0.441</td>
<td valign="top" align="center">0.202</td>
<td valign="top" align="center"><underline>0.536</underline></td>
<td valign="top" align="center"><underline>0.416</underline></td>
<td valign="top" align="center"><underline>0.196</underline></td>
<td valign="top" align="center">0.737</td>
<td valign="top" align="center">0.487</td>
<td valign="top" align="center">0.244</td>
<td valign="top" align="center">4.894</td>
<td valign="top" align="center">2.101</td>
<td valign="top" align="center">0.823</td>
<td valign="top" align="center">4.898</td>
<td valign="top" align="center">2.107</td>
<td valign="top" align="center">0.802</td>
<td valign="top" align="center">1.036</td>
<td valign="top" align="center">0.845</td>
<td valign="top" align="center">0.997</td>
</tr>
<tr>
<td valign="top" align="left" colspan="2">Count</td>
<td valign="top" align="center">16</td>
<td valign="top" align="center">16</td>
<td valign="top" align="center">7</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">8</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p>Optimal avg. metrics are <bold>bolded</bold>; secondary optimal are <underline>underlined</underline>.</p>
</table-wrap-foot>
</table-wrap>
</sec>
<sec>
<title>4.6 Univariate results</title>
<p>Univariate analysis is based solely on the historical data of a single time series to predict future values. In this experiment, we present the univariate results for four datasets (as shown in <xref ref-type="table" rid="T3">Table 3</xref>). Compared to other models, our model (CMDMamba) achieved superior performance in the prediction task. The model uses 96 historical data points to predict 58 future data points), our model reduced the Mean Absolute Error (MAE) on the DAX dataset by 4. 2% (0.522 0.500), on the DJI dataset by 8. 7% (0.344 0.314), on the HSI dataset by 1. 5% ( 0.394 0.388), and on the S&#x00026; P500 dataset by 5. 4% ( 0.185 0.175). Moreover, as the forecasting horizon extends, most baseline models exhibit a noticeable increase in prediction errors&#x02013;specifically in terms of MSE and MAE&#x02013;across various datasets. This trend is particularly evident for models such as Autoformer and Informer, which experience significant error escalation at longer time steps. In contrast, our proposed model, CMDMamba, demonstrates comparatively smaller error growth in most scenarios, highlighting its superior stability in long-term forecasting. However, in terms of MAPE, CMDMamba does not exhibit the same level of dominance as observed in multivariate forecasting tasks. This suggests a potential limitation in univariate settings, where limited input information may constrain the model&#x00027;s ability to effectively capture temporal dependencies.</p>
<table-wrap position="float" id="T3">
<label>Table 3</label>
<caption><p>Univariate forecasting results across four datasets under forecast horizons <italic>O</italic> &#x02208; {12, 36, 58, 96}.</p></caption>
<table frame="box" rules="all">
<thead>
<tr style="background-color:#8f9496;color:#ffffff">
<th valign="top" align="left" colspan="2"><bold>Model</bold></th>
<th valign="top" align="center" colspan="3"><bold>Ours</bold></th>
<th valign="top" align="center" colspan="3"><bold>iTransformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Autoformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Reformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Pyraformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Informer</bold></th>
<th valign="top" align="center" colspan="3"><bold>LSTM</bold></th>
<th valign="top" align="center" colspan="3"><bold>GARCH</bold></th>
</tr>
<tr style="background-color:#8f9496;color:#ffffff">
<td valign="top" align="left" colspan="2" rowspan="2"><bold>Metric</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MSE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAE</bold></td>
<td valign="top" align="center" rowspan="2"><bold>MAPE</bold></td>
</tr> 
</thead>
<tbody>
<tr>
<td valign="top" align="left" rowspan="4">DAX</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.171</bold></td>
<td valign="top" align="center"><bold>0.301</bold></td>
<td valign="top" align="center"><bold>0.151</bold></td>
<td valign="top" align="center"><underline>0.188</underline></td>
<td valign="top" align="center"><underline>0.312</underline></td>
<td valign="top" align="center"><underline>0.162</underline></td>
<td valign="top" align="center">0.751</td>
<td valign="top" align="center">0.684</td>
<td valign="top" align="center">0.248</td>
<td valign="top" align="center">0.809</td>
<td valign="top" align="center">0.791</td>
<td valign="top" align="center">0.443</td>
<td valign="top" align="center">0.271</td>
<td valign="top" align="center">0.417</td>
<td valign="top" align="center">0.324</td>
<td valign="top" align="center">0.489</td>
<td valign="top" align="center">0.588</td>
<td valign="top" align="center">0.424</td>
<td valign="top" align="center">2.280</td>
<td valign="top" align="center">1.400</td>
<td valign="top" align="center">0.475</td>
<td valign="top" align="center">1.026</td>
<td valign="top" align="center">0.828</td>
<td valign="top" align="center">0.998</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.338</bold></td>
<td valign="top" align="center"><bold>0.431</bold></td>
<td valign="top" align="center"><underline>0.225</underline></td>
<td valign="top" align="center"><underline>0.348</underline></td>
<td valign="top" align="center"><underline> 0.441</underline></td>
<td valign="top" align="center"><bold>0.213</bold></td>
<td valign="top" align="center">0.499</td>
<td valign="top" align="center">0.561</td>
<td valign="top" align="center">0.259</td>
<td valign="top" align="center">1.698</td>
<td valign="top" align="center">1.189</td>
<td valign="top" align="center">0.619</td>
<td valign="top" align="center">0.491</td>
<td valign="top" align="center">0.565</td>
<td valign="top" align="center">0.396</td>
<td valign="top" align="center">0.656</td>
<td valign="top" align="center">0.676</td>
<td valign="top" align="center">0.484</td>
<td valign="top" align="center">3.196</td>
<td valign="top" align="center">1.684</td>
<td valign="top" align="center">0.553</td>
<td valign="top" align="center">1.033</td>
<td valign="top" align="center">0.832</td>
<td valign="top" align="center">1.001</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.423</bold></td>
<td valign="top" align="center"><bold>0.522</bold></td>
<td valign="top" align="center"><underline>0.242</underline></td>
<td valign="top" align="center"><underline>0.438</underline></td>
<td valign="top" align="center"><underline>0.500</underline></td>
<td valign="top" align="center"><bold>0.236</bold></td>
<td valign="top" align="center">1.008</td>
<td valign="top" align="center">0.805</td>
<td valign="top" align="center">0.339</td>
<td valign="top" align="center">1.913</td>
<td valign="top" align="center">1.269</td>
<td valign="top" align="center">0.659</td>
<td valign="top" align="center">0.628</td>
<td valign="top" align="center">0.662</td>
<td valign="top" align="center">0.504</td>
<td valign="top" align="center">0.983</td>
<td valign="top" align="center">0.853</td>
<td valign="top" align="center">0.505</td>
<td valign="top" align="center">4.023</td>
<td valign="top" align="center">1.915</td>
<td valign="top" align="center">0.612</td>
<td valign="top" align="center">1.038</td>
<td valign="top" align="center">0.834</td>
<td valign="top" align="center">1.005</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.680</bold></td>
<td valign="top" align="center"><bold>0.634</bold></td>
<td valign="top" align="center"><underline>0.265</underline></td>
<td valign="top" align="center"><underline>0.713</underline></td>
<td valign="top" align="center"><underline>0.664</underline></td>
<td valign="top" align="center"><bold>0.241</bold></td>
<td valign="top" align="center">1.245</td>
<td valign="top" align="center">0.909</td>
<td valign="top" align="center">0.420</td>
<td valign="top" align="center">3.249</td>
<td valign="top" align="center">1.689</td>
<td valign="top" align="center">0.725</td>
<td valign="top" align="center">1.524</td>
<td valign="top" align="center">1.108</td>
<td valign="top" align="center">0.566</td>
<td valign="top" align="center">2.656</td>
<td valign="top" align="center">1.484</td>
<td valign="top" align="center">0.602</td>
<td valign="top" align="center">6.505</td>
<td valign="top" align="center">2.468</td>
<td valign="top" align="center">0.762</td>
<td valign="top" align="center">1.053</td>
<td valign="top" align="center">0.841</td>
<td valign="top" align="center">1.007</td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">DJI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.064</bold></td>
<td valign="top" align="center"><bold>0.182</bold></td>
<td valign="top" align="center"><bold>0.063</bold></td>
<td valign="top" align="center"><underline>0.070</underline></td>
<td valign="top" align="center"><underline>0.188</underline></td>
<td valign="top" align="center"><underline>0.066</underline></td>
<td valign="top" align="center">0.122</td>
<td valign="top" align="center">0.270</td>
<td valign="top" align="center">0.090</td>
<td valign="top" align="center">2.092</td>
<td valign="top" align="center">1.392</td>
<td valign="top" align="center">0.457</td>
<td valign="top" align="center">1.018</td>
<td valign="top" align="center">0.935</td>
<td valign="top" align="center">0.318</td>
<td valign="top" align="center">1.287</td>
<td valign="top" align="center">1.060</td>
<td valign="top" align="center">0.409</td>
<td valign="top" align="center">1.289</td>
<td valign="top" align="center">1.073</td>
<td valign="top" align="center">0.333</td>
<td valign="top" align="center">0.965</td>
<td valign="top" align="center">0.832</td>
<td valign="top" align="center">0.999</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.134</bold></td>
<td valign="top" align="center"><bold>0.267</bold></td>
<td valign="top" align="center"><bold>0.094</bold></td>
<td valign="top" align="center"><underline>0.156</underline></td>
<td valign="top" align="center"><underline>0.284</underline></td>
<td valign="top" align="center"><underline>0.103</underline></td>
<td valign="top" align="center">0.200</td>
<td valign="top" align="center">0.354</td>
<td valign="top" align="center">0.125</td>
<td valign="top" align="center">2.864</td>
<td valign="top" align="center">1.636</td>
<td valign="top" align="center">0.547</td>
<td valign="top" align="center">1.360</td>
<td valign="top" align="center">1.094</td>
<td valign="top" align="center">0.400</td>
<td valign="top" align="center">1.721</td>
<td valign="top" align="center">1.243</td>
<td valign="top" align="center">0.485</td>
<td valign="top" align="center">1.681</td>
<td valign="top" align="center">1.237</td>
<td valign="top" align="center">0.382</td>
<td valign="top" align="center">0.963</td>
<td valign="top" align="center">0.830</td>
<td valign="top" align="center">1.000</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.183</bold></td>
<td valign="top" align="center"><bold>0.314</bold></td>
<td valign="top" align="center"><bold>0.110</bold></td>
<td valign="top" align="center"><underline>0.215</underline></td>
<td valign="top" align="center"><underline>0.344</underline></td>
<td valign="top" align="center"><underline>0.112</underline></td>
<td valign="top" align="center">0.350</td>
<td valign="top" align="center">0.469</td>
<td valign="top" align="center">0.171</td>
<td valign="top" align="center">3.743</td>
<td valign="top" align="center">1.889</td>
<td valign="top" align="center">0.596</td>
<td valign="top" align="center">2.101</td>
<td valign="top" align="center">1.393</td>
<td valign="top" align="center">0.471</td>
<td valign="top" align="center">3.036</td>
<td valign="top" align="center">1.692</td>
<td valign="top" align="center">0.523</td>
<td valign="top" align="center">2.166</td>
<td valign="top" align="center">1.420</td>
<td valign="top" align="center">0.437</td>
<td valign="top" align="center">0.962</td>
<td valign="top" align="center">0.828</td>
<td valign="top" align="center">1.003</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.261</bold></td>
<td valign="top" align="center"><bold>0.382</bold></td>
<td valign="top" align="center"><bold>0.133</bold></td>
<td valign="top" align="center"><underline>0.271</underline></td>
<td valign="top" align="center"><underline>0.388</underline></td>
<td valign="top" align="center"><underline>0.134</underline></td>
<td valign="top" align="center">0.418</td>
<td valign="top" align="center">0.515</td>
<td valign="top" align="center">0.172</td>
<td valign="top" align="center">4.291</td>
<td valign="top" align="center">2.028</td>
<td valign="top" align="center">0.644</td>
<td valign="top" align="center">3.066</td>
<td valign="top" align="center">1.705</td>
<td valign="top" align="center">0.559</td>
<td valign="top" align="center">3.084</td>
<td valign="top" align="center">1.703</td>
<td valign="top" align="center">0.561</td>
<td valign="top" align="center">2.697</td>
<td valign="top" align="center">1.561</td>
<td valign="top" align="center">0.476</td>
<td valign="top" align="center">0.948</td>
<td valign="top" align="center">0.818</td>
<td valign="top" align="center">1.006</td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">HSI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.094</bold></td>
<td valign="top" align="center"><bold>0.242</bold></td>
<td valign="top" align="center">1.498</td>
<td valign="top" align="center"><underline>0.104</underline></td>
<td valign="top" align="center"><underline>0.255</underline></td>
<td valign="top" align="center">1.307</td>
<td valign="top" align="center">0.440</td>
<td valign="top" align="center">0.529</td>
<td valign="top" align="center">2.244</td>
<td valign="top" align="center">0.349</td>
<td valign="top" align="center">0.444</td>
<td valign="top" align="center">1.213</td>
<td valign="top" align="center">0.120</td>
<td valign="top" align="center">0.256</td>
<td valign="top" align="center"><underline>1.070</underline></td>
<td valign="top" align="center">0.275</td>
<td valign="top" align="center">0.402</td>
<td valign="top" align="center">1.975</td>
<td valign="top" align="center">0.228</td>
<td valign="top" align="center">0.371</td>
<td valign="top" align="center">1.735</td>
<td valign="top" align="center">0.993</td>
<td valign="top" align="center">0.815</td>
<td valign="top" align="center"><bold>0.996</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.189</bold></td>
<td valign="top" align="center"><bold>0.334</bold></td>
<td valign="top" align="center">1.581</td>
<td valign="top" align="center"><underline>0.193</underline></td>
<td valign="top" align="center"><underline>0.343</underline></td>
<td valign="top" align="center"><underline>1.480</underline></td>
<td valign="top" align="center">0.270</td>
<td valign="top" align="center">0.409</td>
<td valign="top" align="center">1.920</td>
<td valign="top" align="center">0.515</td>
<td valign="top" align="center">0.561</td>
<td valign="top" align="center">1.488</td>
<td valign="top" align="center">0.247</td>
<td valign="top" align="center">0.370</td>
<td valign="top" align="center">1.683</td>
<td valign="top" align="center">0.354</td>
<td valign="top" align="center">0.473</td>
<td valign="top" align="center">2.288</td>
<td valign="top" align="center">0.431</td>
<td valign="top" align="center">0.525</td>
<td valign="top" align="center">2.583</td>
<td valign="top" align="center">0.974</td>
<td valign="top" align="center">0.810</td>
<td valign="top" align="center"><bold>1.001</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.245</bold></td>
<td valign="top" align="center"><bold>0.388</bold></td>
<td valign="top" align="center">2.199</td>
<td valign="top" align="center"><underline>0.255</underline></td>
<td valign="top" align="center"><underline>0.394</underline></td>
<td valign="top" align="center">2.309</td>
<td valign="top" align="center">0.633</td>
<td valign="top" align="center">0.672</td>
<td valign="top" align="center">3.862</td>
<td valign="top" align="center">0.695</td>
<td valign="top" align="center">0.685</td>
<td valign="top" align="center"><underline>1.746</underline></td>
<td valign="top" align="center">0.364</td>
<td valign="top" align="center">0.460</td>
<td valign="top" align="center">2.035</td>
<td valign="top" align="center">0.649</td>
<td valign="top" align="center">0.658</td>
<td valign="top" align="center">2.375</td>
<td valign="top" align="center">0.664</td>
<td valign="top" align="center">0.693</td>
<td valign="top" align="center">3.809</td>
<td valign="top" align="center">0.959</td>
<td valign="top" align="center">0.805</td>
<td valign="top" align="center"><bold>1.002</bold></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.430</bold></td>
<td valign="top" align="center"><underline>0.535</underline></td>
<td valign="top" align="center">3.668</td>
<td valign="top" align="center"><underline>0.435</underline></td>
<td valign="top" align="center"><bold>0.531</bold></td>
<td valign="top" align="center">3.986</td>
<td valign="top" align="center">0.886</td>
<td valign="top" align="center">0.815</td>
<td valign="top" align="center">5.112</td>
<td valign="top" align="center">0.665</td>
<td valign="top" align="center">0.660</td>
<td valign="top" align="center"><underline>1.890</underline></td>
<td valign="top" align="center">0.701</td>
<td valign="top" align="center">0.666</td>
<td valign="top" align="center">2.747</td>
<td valign="top" align="center">0.877</td>
<td valign="top" align="center">0.726</td>
<td valign="top" align="center">4.502</td>
<td valign="top" align="center">0.979</td>
<td valign="top" align="center">0.892</td>
<td valign="top" align="center">4.041</td>
<td valign="top" align="center">0.926</td>
<td valign="top" align="center">0.796</td>
<td valign="top" align="center"><bold>1.006</bold></td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">S&#x00026;P500</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.032</bold></td>
<td valign="top" align="center"><bold>0.147</bold></td>
<td valign="top" align="center"><underline>0.061</underline></td>
<td valign="top" align="center"><underline>0.035</underline></td>
<td valign="top" align="center"><underline>0.148</underline></td>
<td valign="top" align="center"><bold>0.059</bold></td>
<td valign="top" align="center">0.121</td>
<td valign="top" align="center">0.263</td>
<td valign="top" align="center">0.130</td>
<td valign="top" align="center">0.470</td>
<td valign="top" align="center">0.556</td>
<td valign="top" align="center">0.247</td>
<td valign="top" align="center">0.118</td>
<td valign="top" align="center">0.281</td>
<td valign="top" align="center">0.087</td>
<td valign="top" align="center">0.122</td>
<td valign="top" align="center">0.281</td>
<td valign="top" align="center">0.207</td>
<td valign="top" align="center">0.258</td>
<td valign="top" align="center">0.437</td>
<td valign="top" align="center">0.157</td>
<td valign="top" align="center">1.040</td>
<td valign="top" align="center">0.884</td>
<td valign="top" align="center">1.000</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><underline>0.052</underline></td>
<td valign="top" align="center"><underline>0.179</underline></td>
<td valign="top" align="center"><bold>0.073</bold></td>
<td valign="top" align="center"><bold>0.048</bold></td>
<td valign="top" align="center"><bold>0.170</bold></td>
<td valign="top" align="center"><bold>0.073</bold></td>
<td valign="top" align="center">0.154</td>
<td valign="top" align="center">0.317</td>
<td valign="top" align="center"><underline>0.135</underline></td>
<td valign="top" align="center">1.262</td>
<td valign="top" align="center">0.993</td>
<td valign="top" align="center">0.423</td>
<td valign="top" align="center">0.767</td>
<td valign="top" align="center">0.771</td>
<td valign="top" align="center">0.312</td>
<td valign="top" align="center">0.493</td>
<td valign="top" align="center">0.594</td>
<td valign="top" align="center">0.264</td>
<td valign="top" align="center">0.362</td>
<td valign="top" align="center">0.522</td>
<td valign="top" align="center">0.187</td>
<td valign="top" align="center">1.039</td>
<td valign="top" align="center">0.882</td>
<td valign="top" align="center">1.002</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.051</bold></td>
<td valign="top" align="center"><bold>0.175</bold></td>
<td valign="top" align="center"><bold>0.073</bold></td>
<td valign="top" align="center"><underline>0.057</underline></td>
<td valign="top" align="center"><underline>0.185</underline></td>
<td valign="top" align="center"><underline>0.079</underline></td>
<td valign="top" align="center">0.194</td>
<td valign="top" align="center">0.353</td>
<td valign="top" align="center">0.150</td>
<td valign="top" align="center">1.353</td>
<td valign="top" align="center">1.054</td>
<td valign="top" align="center">0.508</td>
<td valign="top" align="center">1.025</td>
<td valign="top" align="center">0.920</td>
<td valign="top" align="center">0.351</td>
<td valign="top" align="center">0.423</td>
<td valign="top" align="center">0.558</td>
<td valign="top" align="center">0.344</td>
<td valign="top" align="center">0.455</td>
<td valign="top" align="center">0.609</td>
<td valign="top" align="center">0.221</td>
<td valign="top" align="center">1.037</td>
<td valign="top" align="center">0.883</td>
<td valign="top" align="center">1.006</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.065</bold></td>
<td valign="top" align="center"><bold>0.202</bold></td>
<td valign="top" align="center"><bold>0.081</bold></td>
<td valign="top" align="center"><underline>0.080</underline></td>
<td valign="top" align="center"><underline>0.225</underline></td>
<td valign="top" align="center"><underline>0.095</underline></td>
<td valign="top" align="center">0.169</td>
<td valign="top" align="center">0.325</td>
<td valign="top" align="center">0.153</td>
<td valign="top" align="center">2.221</td>
<td valign="top" align="center">1.422</td>
<td valign="top" align="center">0.647</td>
<td valign="top" align="center">1.538</td>
<td valign="top" align="center">1.174</td>
<td valign="top" align="center">0.465</td>
<td valign="top" align="center">1.223</td>
<td valign="top" align="center">1.040</td>
<td valign="top" align="center">0.472</td>
<td valign="top" align="center">1.756</td>
<td valign="top" align="center">1.252</td>
<td valign="top" align="center">0.468</td>
<td valign="top" align="center">1.029</td>
<td valign="top" align="center">0.878</td>
<td valign="top" align="center">1.009</td>
</tr>
<tr>
<td valign="top" align="left" colspan="2">Count</td>
<td valign="top" align="center">15</td>
<td valign="top" align="center">13</td>
<td valign="top" align="center">8</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">3</td>
<td valign="top" align="center">5</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">4</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p>Optimal avg. metrics are <bold>bolded</bold>; secondary optimal are <underline>underlined</underline>.</p>
</table-wrap-foot>
</table-wrap>
</sec>
<sec>
<title>4.7 Ablation experment</title>
<p>To evaluate the impact of the dual-layer Mamba and DconvFFN on CMDMamba&#x00027;s performance, we conduct an ablation study examining three model variants: tFFN/oMamba, which integrates the DconvFFN module alongside a single Mamba layer; oFFN/tMamba, which excludes the DconvFFN module but incorporates two Mamba layers; and oFFN/oMamba, which omits both the DconvFFN module and Mamba layers. We compare these variants against Reformer and Transformer models across four datasets, utilizing MSE and MAE as evaluation metrics. As presented in <xref ref-type="table" rid="T4">Table 4</xref>, the results indicate a progressive enhancement in model performance with the inclusion of additional components. This confirms the substantial contribution of both the dual-layer Mamba and DconvFFN module to the overall effectiveness of CMDMamba.</p>
<table-wrap position="float" id="T4">
<label>Table 4</label>
<caption><p>Ablative experiment results across four datasets under forecast horizons <italic>O</italic> &#x02208; {12, 36, 58, 96}.</p></caption>
<table frame="box" rules="all">
<thead>
<tr style="background-color:#8f9496;color:#ffffff">
<th valign="top" align="left" colspan="2"><bold>Model</bold></th>
<th valign="top" align="center" colspan="3"><bold>Ours</bold></th>
<th valign="top" align="center" colspan="3"><bold>tFFN/oMamba</bold></th>
<th valign="top" align="center" colspan="3"><bold>oFFN/tMamba</bold></th>
<th valign="top" align="center" colspan="3"><bold>oFFN/oMamba</bold></th>
<th valign="top" align="center" colspan="3"><bold>Reformer</bold></th>
<th valign="top" align="center" colspan="3"><bold>Transformer</bold></th>
</tr>
</thead>
<tbody>
<tr style="background-color:#8f9496;color:#ffffff">
<td valign="top" align="left" colspan="2"><bold>Metric</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
<td valign="top" align="center"><bold>MSE</bold></td>
<td valign="top" align="center"><bold>MAE</bold></td>
<td valign="top" align="center"><bold>MAPE</bold></td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">DAX</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.246</bold></td>
<td valign="top" align="center"><bold>0.351</bold></td>
<td valign="top" align="center"><underline>1.182</underline></td>
<td valign="top" align="center"><underline> 0.253</underline></td>
<td valign="top" align="center"><underline>0.357</underline></td>
<td valign="top" align="center"><bold>1.181</bold></td>
<td valign="top" align="center">0.259</td>
<td valign="top" align="center">0.363</td>
<td valign="top" align="center">1.315</td>
<td valign="top" align="center">0.271</td>
<td valign="top" align="center">0.370</td>
<td valign="top" align="center">1.429</td>
<td valign="top" align="center">1.086</td>
<td valign="top" align="center">0.873</td>
<td valign="top" align="center">1.450</td>
<td valign="top" align="center">0.877</td>
<td valign="top" align="center">0.797</td>
<td valign="top" align="center">1.363</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.413</bold></td>
<td valign="top" align="center"><bold>0.464</bold></td>
<td valign="top" align="center"><bold>1.390</bold></td>
<td valign="top" align="center">0.422</td>
<td valign="top" align="center"><underline>0.470</underline></td>
<td valign="top" align="center"><underline>1.396</underline></td>
<td valign="top" align="center">0.422</td>
<td valign="top" align="center">0.478</td>
<td valign="top" align="center">1.735</td>
<td valign="top" align="center"><underline>0.420</underline></td>
<td valign="top" align="center">0.474</td>
<td valign="top" align="center">1.799</td>
<td valign="top" align="center">2.106</td>
<td valign="top" align="center">1.243</td>
<td valign="top" align="center">1.576</td>
<td valign="top" align="center">1.153</td>
<td valign="top" align="center">0.922</td>
<td valign="top" align="center">1.431</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.504</bold></td>
<td valign="top" align="center"><bold>0.520</bold></td>
<td valign="top" align="center"><bold>1.321</bold></td>
<td valign="top" align="center">0.515</td>
<td valign="top" align="center"><underline>0.527</underline></td>
<td valign="top" align="center"><underline>1.327</underline></td>
<td valign="top" align="center"><underline>0.505</underline></td>
<td valign="top" align="center">0.528</td>
<td valign="top" align="center">1.642</td>
<td valign="top" align="center">0.509</td>
<td valign="top" align="center">0.529</td>
<td valign="top" align="center">1.711</td>
<td valign="top" align="center">2.356</td>
<td valign="top" align="center">1.322</td>
<td valign="top" align="center">1.598</td>
<td valign="top" align="center">1.173</td>
<td valign="top" align="center">0.919</td>
<td valign="top" align="center">1.470</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center">0.714</td>
<td valign="top" align="center">0.641</td>
<td valign="top" align="center"><underline>1.452</underline></td>
<td valign="top" align="center"><underline>0.646</underline></td>
<td valign="top" align="center"><bold>0.602</bold></td>
<td valign="top" align="center"><bold>1.449</bold></td>
<td valign="top" align="center"><bold>0.643</bold></td>
<td valign="top" align="center"><underline>0.604</underline></td>
<td valign="top" align="center">1.650</td>
<td valign="top" align="center">0.649</td>
<td valign="top" align="center">0.607</td>
<td valign="top" align="center">1.736</td>
<td valign="top" align="center">3.261</td>
<td valign="top" align="center">1.578</td>
<td valign="top" align="center">1.684</td>
<td valign="top" align="center">2.372</td>
<td valign="top" align="center">1.334</td>
<td valign="top" align="center">0.549</td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">DJI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><underline>0.128</underline></td>
<td valign="top" align="center"><underline>0.245</underline></td>
<td valign="top" align="center">0.395</td>
<td valign="top" align="center"><bold>0.126</bold></td>
<td valign="top" align="center">0.244</td>
<td valign="top" align="center">0.395</td>
<td valign="top" align="center">0.129</td>
<td valign="top" align="center"><bold>0.243</bold></td>
<td valign="top" align="center"><underline>0.391</underline></td>
<td valign="top" align="center">0.134</td>
<td valign="top" align="center">0.250</td>
<td valign="top" align="center"><bold>0.387</bold></td>
<td valign="top" align="center">2.001</td>
<td valign="top" align="center">1.300</td>
<td valign="top" align="center">0.439</td>
<td valign="top" align="center">1.309</td>
<td valign="top" align="center">1.035</td>
<td valign="top" align="center">0.442</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><bold>0.170</bold></td>
<td valign="top" align="center"><bold>0.298</bold></td>
<td valign="top" align="center">0.429</td>
<td valign="top" align="center"><underline>0.175</underline></td>
<td valign="top" align="center">0.301</td>
<td valign="top" align="center">0.429</td>
<td valign="top" align="center">0.176</td>
<td valign="top" align="center"><underline>0.300</underline></td>
<td valign="top" align="center"><underline>0.465</underline></td>
<td valign="top" align="center">0.179</td>
<td valign="top" align="center">0.305</td>
<td valign="top" align="center"><bold>0.455</bold></td>
<td valign="top" align="center">2.499</td>
<td valign="top" align="center">1.457</td>
<td valign="top" align="center">0.560</td>
<td valign="top" align="center">1.707</td>
<td valign="top" align="center">1.214</td>
<td valign="top" align="center">0.577</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.197</bold></td>
<td valign="top" align="center"><bold>0.325</bold></td>
<td valign="top" align="center"><underline>0.482</underline></td>
<td valign="top" align="center"><underline>0.198</underline></td>
<td valign="top" align="center"><underline>0.326</underline></td>
<td valign="top" align="center"><bold>0.481</bold></td>
<td valign="top" align="center">0.204</td>
<td valign="top" align="center">0.330</td>
<td valign="top" align="center">0.504</td>
<td valign="top" align="center">0.206</td>
<td valign="top" align="center">0.331</td>
<td valign="top" align="center">0.488</td>
<td valign="top" align="center">2.802</td>
<td valign="top" align="center">1.548</td>
<td valign="top" align="center">0.558</td>
<td valign="top" align="center">2.180</td>
<td valign="top" align="center">1.363</td>
<td valign="top" align="center">0.536</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.261</bold></td>
<td valign="top" align="center"><underline>0.391</underline></td>
<td valign="top" align="center"><underline>0.548</underline></td>
<td valign="top" align="center"><underline>0.262 </underline></td>
<td valign="top" align="center"><bold>0.390</bold></td>
<td valign="top" align="center"><bold>0.547</bold></td>
<td valign="top" align="center">0.266</td>
<td valign="top" align="center">0.393</td>
<td valign="top" align="center">0.609</td>
<td valign="top" align="center">0.264</td>
<td valign="top" align="center">0.391</td>
<td valign="top" align="center">0.587</td>
<td valign="top" align="center">3.562</td>
<td valign="top" align="center">1.746</td>
<td valign="top" align="center">0.637</td>
<td valign="top" align="center">2.463</td>
<td valign="top" align="center">1.461</td>
<td valign="top" align="center">0.589</td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">HSI</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><bold>0.323</bold></td>
<td valign="top" align="center"><underline>0.352</underline></td>
<td valign="top" align="center">2.530</td>
<td valign="top" align="center"><bold>0.323</bold></td>
<td valign="top" align="center"><bold>0.349</bold></td>
<td valign="top" align="center">2.525</td>
<td valign="top" align="center">0.351</td>
<td valign="top" align="center">0.359</td>
<td valign="top" align="center">2.369</td>
<td valign="top" align="center"><underline>0.347</underline></td>
<td valign="top" align="center">0.359</td>
<td valign="top" align="center">2.389</td>
<td valign="top" align="center">0.435</td>
<td valign="top" align="center">0.440</td>
<td valign="top" align="center"><bold>1.145</bold></td>
<td valign="top" align="center">0.491</td>
<td valign="top" align="center">0.467</td>
<td valign="top" align="center"><underline>1.395</underline></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><underline>0.434</underline></td>
<td valign="top" align="center">0.449</td>
<td valign="top" align="center">3.159</td>
<td valign="top" align="center"><bold>0.429</bold></td>
<td valign="top" align="center"><underline>0.448</underline></td>
<td valign="top" align="center">3.164</td>
<td valign="top" align="center">0.460</td>
<td valign="top" align="center">0.457</td>
<td valign="top" align="center">3.215</td>
<td valign="top" align="center">0.442</td>
<td valign="top" align="center"><bold>0.438</bold></td>
<td valign="top" align="center">3.277</td>
<td valign="top" align="center">0.692</td>
<td valign="top" align="center">0.594</td>
<td valign="top" align="center"><bold>1.595</bold></td>
<td valign="top" align="center">0.522</td>
<td valign="top" align="center">0.520</td>
<td valign="top" align="center"><underline>1.982</underline></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center">0.561</td>
<td valign="top" align="center">0.519</td>
<td valign="top" align="center">4.256</td>
<td valign="top" align="center"><bold>0.517</bold></td>
<td valign="top" align="center"><bold>0.502</bold></td>
<td valign="top" align="center">4.267</td>
<td valign="top" align="center">0.565</td>
<td valign="top" align="center">0.522</td>
<td valign="top" align="center">3.944</td>
<td valign="top" align="center"><underline>0.549</underline></td>
<td valign="top" align="center"><underline>0.513</underline></td>
<td valign="top" align="center">4.313</td>
<td valign="top" align="center">0.875</td>
<td valign="top" align="center">0.737</td>
<td valign="top" align="center"><bold>1.454</bold></td>
<td valign="top" align="center">0.573</td>
<td valign="top" align="center">0.547</td>
<td valign="top" align="center"><underline>2.585</underline></td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><bold>0.695</bold></td>
<td valign="top" align="center"><bold>0.629</bold></td>
<td valign="top" align="center">5.172</td>
<td valign="top" align="center"><underline>0.724</underline></td>
<td valign="top" align="center"><underline>0.648</underline></td>
<td valign="top" align="center">5.179</td>
<td valign="top" align="center">0.753</td>
<td valign="top" align="center">0.654</td>
<td valign="top" align="center">5.831</td>
<td valign="top" align="center">0.747</td>
<td valign="top" align="center">0.653</td>
<td valign="top" align="center">6.037</td>
<td valign="top" align="center">0.995</td>
<td valign="top" align="center">0.763</td>
<td valign="top" align="center"><bold>2.232</bold></td>
<td valign="top" align="center">0.782</td>
<td valign="top" align="center">0.700</td>
<td valign="top" align="center"><underline>3.443</underline></td>
</tr> <tr>
<td valign="top" align="left" rowspan="4">S&#x00026;P500</td>
<td valign="top" align="center"><bold>12</bold></td>
<td valign="top" align="center"><underline>0.394</underline></td>
<td valign="top" align="center"><underline>0.292</underline></td>
<td valign="top" align="center"><underline>0.243</underline></td>
<td valign="top" align="center"><bold>0.364</bold></td>
<td valign="top" align="center"><bold>0.285</bold></td>
<td valign="top" align="center"><underline>0.243</underline></td>
<td valign="top" align="center">0.479</td>
<td valign="top" align="center">0.323</td>
<td valign="top" align="center">0.256</td>
<td valign="top" align="center">0.453</td>
<td valign="top" align="center">0.322</td>
<td valign="top" align="center">0.284</td>
<td valign="top" align="center">1.926</td>
<td valign="top" align="center">0.799</td>
<td valign="top" align="center"><bold>0.226</bold></td>
<td valign="top" align="center">2.070</td>
<td valign="top" align="center">0.892</td>
<td valign="top" align="center">0.277</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>24</bold></td>
<td valign="top" align="center"><underline>0.462</underline></td>
<td valign="top" align="center"><underline>0.352</underline></td>
<td valign="top" align="center">0.229</td>
<td valign="top" align="center"><bold>0.456</bold></td>
<td valign="top" align="center"><bold>0.329</bold></td>
<td valign="top" align="center">0.229</td>
<td valign="top" align="center">0.520</td>
<td valign="top" align="center">0.354</td>
<td valign="top" align="center"><bold>0.222</bold></td>
<td valign="top" align="center">0.520</td>
<td valign="top" align="center">0.355</td>
<td valign="top" align="center"><underline>0.225</underline></td>
<td valign="top" align="center">3.104</td>
<td valign="top" align="center">1.612</td>
<td valign="top" align="center">0.424</td>
<td valign="top" align="center">1.793</td>
<td valign="top" align="center">1.233</td>
<td valign="top" align="center">0.259</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>36</bold></td>
<td valign="top" align="center"><bold>0.447</bold></td>
<td valign="top" align="center"><bold>0.343</bold></td>
<td valign="top" align="center"><bold>0.164</bold></td>
<td valign="top" align="center"><underline>0.457</underline></td>
<td valign="top" align="center"><underline>0.348</underline></td>
<td valign="top" align="center"><underline>0.165</underline></td>
<td valign="top" align="center">0.505</td>
<td valign="top" align="center">0.358</td>
<td valign="top" align="center">0.178</td>
<td valign="top" align="center">0.504</td>
<td valign="top" align="center">0.362</td>
<td valign="top" align="center">0.184</td>
<td valign="top" align="center">3.541</td>
<td valign="top" align="center">1.734</td>
<td valign="top" align="center">0.487</td>
<td valign="top" align="center">2.000</td>
<td valign="top" align="center">1.281</td>
<td valign="top" align="center">0.202</td>
</tr>
 <tr>

<td valign="top" align="center"><bold>96</bold></td>
<td valign="top" align="center"><underline>0.502</underline></td>
<td valign="top" align="center"><underline>0.399</underline></td>
<td valign="top" align="center">0.198</td>
<td valign="top" align="center"><bold>0.498</bold></td>
<td valign="top" align="center"><bold>0.376</bold></td>
<td valign="top" align="center"><underline>0.197</underline></td>
<td valign="top" align="center">0.558</td>
<td valign="top" align="center">0.402</td>
<td valign="top" align="center"><bold>0.193</bold></td>
<td valign="top" align="center">0.565</td>
<td valign="top" align="center">0.397</td>
<td valign="top" align="center">0.208</td>
<td valign="top" align="center">4.608</td>
<td valign="top" align="center">2.017</td>
<td valign="top" align="center">0.634</td>
<td valign="top" align="center">2.725</td>
<td valign="top" align="center">1.516</td>
<td valign="top" align="center">0.218</td>
</tr>
<tr>
<td valign="top" align="left" colspan="2">Count</td>
<td valign="top" align="center">9</td>
<td valign="top" align="center">7</td>
<td valign="top" align="center">3</td>
<td valign="top" align="center">7</td>
<td valign="top" align="center">7</td>
<td valign="top" align="center">4</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">2</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">1</td>
<td valign="top" align="center">2</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">5</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
<td valign="top" align="center">0</td>
</tr></tbody>
</table>
<table-wrap-foot>
<p>Optimal avg. metrics are <bold>bolded</bold>; secondary optimal are <underline>underlined</underline>.</p>
</table-wrap-foot>
</table-wrap>
</sec>
</sec>
<sec sec-type="discussion" id="s5">
<title>5 Discussion</title>
<sec>
<title>5.1 Hyper-parameter sensitivity analysis</title>
<p>To rigorously assess the parameter sensitivity of CMDMamba, we systematically examined two pivotal hyperparameters through cross-market evaluations using datasets representing diverse economic environments: (a) dropout rate and (b) SSM state expansion factor. Our experimental protocol maintained fixed non-target parameters while executing five independent training runs per configuration, each spanning 30 epochs with early stopping monitoring validation loss (patience threshold = 5 epochs). Model performance was rigorously evaluated using MSE metrics across four distinct forecast horizons <inline-formula><mml:math id="M19"><mml:mrow><mml:mi mathvariant="script">O</mml:mi></mml:mrow><mml:mo>&#x02208;</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mrow><mml:mn>12</mml:mn><mml:mo>,</mml:mo><mml:mn>36</mml:mn><mml:mo>,</mml:mo><mml:mn>58</mml:mn><mml:mo>,</mml:mo><mml:mn>96</mml:mn></mml:mrow><mml:mo>}</mml:mo></mml:mrow></mml:math></inline-formula>.. This approach aligns with the rigorous evaluation methodologies used in recent studies on hyperparameter tuning for deep learning models in time series forecasting, ensuring that our findings are comparable and robust.</p>
<sec>
<title>5.1.1 Dropout</title>
<p>In our architecture, the dropout mechanism is implemented within the DconvFFN layers (as illustrated in <xref ref-type="fig" rid="F4">Figure 4</xref>). This technique alleviates overfitting and enhances model generalization by randomly zeroing out each element of the input tensor with probability <italic>p</italic>. Systematic comparisons of dropout rates <italic>p</italic> &#x02208; {0.05, 0.1, 0.15, 0.2} demonstrate that the model achieves optimal overall performance at <italic>p</italic> &#x0003D; 0.1. The results indicate that insufficient regularization occurs with excessively low dropout rates, while overly high dropout rates degrade performance by impairing the representational capacity of the deep convolutional feed-forward network.</p>
<fig id="F4" position="float">
<label>Figure 4</label>
<caption><p>Experiment on the sensitivity of model to dropout.</p></caption>
<alt-text>Two line graphs compare the sensitivity of dropout on HSI and S&#x00026;P500 with dropout rates ranging from 0.05 to 0.2. The y-axis shows MSE values. Four data series are represented with different markers and colors: grey diamonds for 12, green triangles for 36, red circles for 58, and purple squares for 96. Both graphs show minor variations in MSE values across different dropout rates. The HSI graph has higher MSE values compared to the S&#x00026;P500 graph.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0004.tif"/>
</fig>
</sec>
<sec>
<title>5.1.2 SSM state expansion factor</title>
<p>This study examines the impact of the expansion factor <italic>M</italic> in state space models on time series forecasting performance. The experimental results are shown in <xref ref-type="fig" rid="F5">Figure 5</xref>. When <italic>M</italic> &#x02208; {2, 4, 8, 16}, distinct patterns emerge: In the S&#x00026;P500 dataset, which represents global multi-market dynamics, forecasting accuracy significantly improves as <italic>M</italic> increases. This confirms that cross-market linkage effects require higher-dimensional latent states for effective capture. Conversely, in the regionally focused HSI (Hang Seng Index) dataset, variations in <italic>M</italic> have almost no impact. This suggests that its endogenous temporal patterns exhibit low-dimensional separability, where excessive expansion of the state dimension may introduce noise interference.</p>
<fig id="F5" position="float">
<label>Figure 5</label>
<caption><p>Model sensitivity to SSM state expansion factor experiment.</p></caption>
<alt-text>Two line graphs show the sensitivity of the state expansion factor M on MSE for HSI and S&#x00026;P 500. The left graph indicates MSE ranging from 0.3 to 0.8, with four lines representing different values (12, 36, 58, 96). The right graph shows MSE from 0.36 to 0.52, with similar lines. Both graphs plot MSE against M values (2, 4, 8, 16).</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0005.tif"/>
</fig>
</sec>
</sec>
<sec>
<title>5.2 Generalization and predictive insights of the model on stock values</title>
<p>Based on the high accuracy demonstrated by the CMDMamba model in predicting closing prices (Close), we further evaluated its generalization capability through experiments on two distinct market economy datasets: the regional HSI and the globally representative S&#x00026;P500 Index. Our study extended the model&#x00027;s application to four additional crucial price variables&#x02014;opening price (Open), highest price (High), lowest price (Low), and adjusted closing price (Adj Close)&#x02014;which represent various aspects of financial market behavior. As illustrated in <xref ref-type="fig" rid="F6">Figure 6</xref>, the CMDMamba model exhibits superior performance in these diverse stock price prediction tasks.</p>
<fig id="F6" position="float">
<label>Figure 6</label>
<caption><p>Prediction results of stock price variables by different models with input length <italic>L</italic> &#x0003D; 96 and forecast horizon <italic>O</italic> &#x0003D; 12.</p></caption>
<alt-text>Bar graphs comparing different methods for predicting stock metrics. Top-left graph shows mean squared error (MSE) for HSI with "Ours" as one method. Top-right graph shows mean absolute error (MAE) for HSI. Bottom-left graph shows MSE for S&#x00026;P500. Bottom-right graph shows MAE for S&#x00026;P500. Each bar represents a prediction method, including S_Mamba, iTransformer, Autoformer, and FiLM. Metrics include Open, High, Low, and Adjusted Close.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0006.tif"/>
</fig>
</sec>
<sec>
<title>5.3 Model efficiency</title>
<p>In this experiment, we comprehensively evaluated model efficiency from three dimensions: (a) predictive accuracy, (b) memory usage, and (c) training speed. For the prediction task, we set <italic>L</italic> &#x0003D; 96 (input length), <italic>O</italic> &#x0003D; 12 (forecast horizon), and <italic>B</italic> &#x0003D; 8 (batch size), with results presented in <xref ref-type="fig" rid="F7">Figure 7</xref>. All other parameters were fixed to ensure modeling consistency. A direct comparison was made between the self-attention mechanism and CMDMamba. In HSI data tests focusing on regional markets, iTransformer demonstrated marginally superior computational efficiency compared to CMDMamba. However, CMDMamba achieved better prediction performance and memory optimization, showing particular effectiveness in capturing temporal patterns in relatively stable sequences. For the S&#x00026;P500 dataset representing global multi-market dynamics, both CMDMamba and self-attention-based models exhibited strong predictive capabilities in volatile market conditions. Notably, CMDMamba outperformed all counterparts across both datasets. This advantage stems from the linear complexity characteristics of SSM, enabling CMDMamba to achieve an optimal balance between prediction accuracy, training speed, and memory consumption. This finding is consistent with recent advancements in efficient sequence modeling, where linear complexity models are increasingly preferred over quadratic complexity models for large-scale applications. Overall, compared to self-attention mechanisms in Transformers with equivalent embedding dimension <italic>D</italic>, CMDMamba demonstrates significantly lower computational costs, particularly evident in training speed and GPU memory utilization. With superior predictive performance, accelerated training efficiency, and reduced memory requirements, Mamba-like models exhibit great potential for financial time series forecasting applications.</p>
<fig id="F7" position="float">
<label>Figure 7</label>
<caption><p>Comparison of model efficiency on HSI and S&#x00026;P500 datasets with sequence length <italic>L</italic> &#x0003D; 96 and forecast horizon <italic>O</italic> &#x0003D; 12, using a batch size of 12.</p></caption>
<alt-text>Scatter plots comparing multiple machine learning models on HSI and S&#x00026;P500 datasets, showing Mean Squared Error (MSE) versus speed (ms/iteration). Models include iTransformer, Reformer, Informer, Crossformer, Autoformer, and Transformer, with memory footprints indicated by circle size.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0007.tif"/>
</fig>
</sec>
<sec>
<title>5.4 Performance under different input sequences</title>
<p>The selection of an appropriate review window size is critical for time series forecasting models, as it determines the extent to which historical dependencies can be captured. A proficient forecasting model should be capable of learning long-term dependencies by expanding the review window, thereby enhancing predictive accuracy. In our experimental design, we maintained a fixed forecast horizon (&#x0003D; 12) across two heterogeneous datasets while systematically varying the review window sizes ( &#x02208; {12, 36, 58, 96}), ensuring that all other model parameters remained constant to facilitate a reliable comparative analysis. As illustrated in <xref ref-type="fig" rid="F8">Figure 8</xref>, the CMDMamba model consistently outperforms across all review window configurations, demonstrating its robust forecasting capability. This empirical advantage can be attributed to two key architectural innovations. First, the DconvFFN module efficiently captures multivariate feature dependencies by leveraging dilated convolutional operations. Second, the dual-layer Mamba architecture integrates differentially sensitized modules: the shallower layer specializes in detecting local fluctuations within shorter review windows through high-frequency filtering, while the deeper layer focuses on extracting global dependencies in extended sequences via low-frequency pattern analysis. These design principles collectively enable CMDMamba to achieve superior forecasting performance across diverse time series scenarios.</p>
<fig id="F8" position="float">
<label>Figure 8</label>
<caption><p>Predicted line graphs of two datasets across different review windows. We compare these with four other models.</p></caption>
<alt-text>Two line graphs compare the Mean Squared Error (MSE) across various review window sizes for different methods on HSI and S&#x00026;P500 datasets. The methods include Film, S Mamba, Autoformer, iTransformer, and Ours. The graphs show that the &#x0201C;Ours&#x0201D; method consistently has the lowest MSE across all review window sizes for both datasets.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0008.tif"/>
</fig>
</sec>
<sec>
<title>5.5 Comparison of different deep learning models</title>
<p>In this study, we systematically evaluated the performance of four mainstream architectures&#x02013;state-space models, Transformer, temporal convolution, and MLP&#x02013;in financial time series forecasting using datasets such as HSI and S&#x00026;P500. As shown in <xref ref-type="fig" rid="F9">Figure 9</xref>, compared with the iTransformer, which also has the ability to model global dependencies, the CMDMamba based on Mamba not only demonstrates superior predictive performance but also optimizes the computational complexity to linear. When compared with SCINet, which has a convolutional module, CMDMamba can better capture global dependencies through its selective attention mechanism, showing significant performance advantages over temporal convolutional models. Compared with the MLP-based TiDE, CMDMamba employs a dual-layer Mamba framework that can adaptively enhance attention weights for recent abnormal fluctuations, while the static processing mode of the MLP lacks flexibility in responding to market dynamics. These findings indicate that Mamba, as an emerging deep learning framework, shows great potential and broad application prospects in financial sequence prediction by balancing computational efficiency and the ability to model global dependencies.</p>
<fig id="F9" position="float">
<label>Figure 9</label>
<caption><p>3D graphs of different deep learning frameworks on two datasets, presenting the results achieved for different forecast horizons <italic>O</italic> &#x02208; {12, 36, 58, 96}.</p></caption>
<alt-text>Two 3D bar graphs comparing the performance of three models&#x02013;SCINet, TiDE, and Our Transform&#x02013;in predicting HSI and S&#x00026;P500 indices across different prediction lengths (12, 36, 58, 96). The vertical axis represents Mean Squared Error (MSE). The left graph for HSI shows decreasing MSE values from SCINet to TiDE to Our Transform. The right graph for S&#x00026;P500 displays a similar trend with slightly higher initial MSE values. The colors differentiate the models: blue for SCINet, green for TiDE, and orange for Our Transform.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0009.tif"/>
</fig>
</sec>
<sec>
<title>5.6 Model&#x00027;s adaptability to noise</title>
<p>This study systematically evaluates the robustness of the CMDMamba model against noise interference in financial time series data, addressing the pervasive challenges of multidimensional game noise and market information friction. Experiments applied 50% and 100% Gaussian white noise to the HSI and S&#x00026;P500 datasets, simulating variations in the signal-to-noise ratio (SNR) in real-world markets. The results (see <xref ref-type="fig" rid="F10">Figure 10</xref>) show that CMDMamba outperforms Transformer-based architectures in both dynamic noise testing and cross-market validation. The model&#x00027;s dual-layer Mamba mechanism can effectively suppress noise while maintaining linear computational complexity. Compared to self-attention mechanisms, this approach reduces redundancy and achieves precise noise-signal separation in complex financial environments.</p>
<fig id="F10" position="float">
<label>Figure 10</label>
<caption><p>Prediction results reveal the noise resistance performance of different models on HSI and S&#x00026;P500 datasets with input length <italic>L</italic> &#x0003D; 96 and forecast horizon <italic>O</italic> &#x0003D; 12.</p></caption>
<alt-text>Two bar charts compare model performance using Mean Squared Error (MSE) for HSI and S&#x00026;P500. The models are Ours, S_Mamba, iTransformer, and Autoformer. Each model&#x00027;s performance is evaluated at 50% and 100% data input, with Autoformer showing the highest MSE in both cases.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0010.tif"/>
</fig>
</sec>
<sec>
<title>5.7 Impact analysis of price features on model performance</title>
<p>This study employs a univariate forecasting approach to systematically assess the impact of six key financial indicators on model performance across varying input sequence lengths <italic>L</italic> &#x02208; {12, 36, 58, 96}, as shown in <xref ref-type="fig" rid="F11">Figure 11</xref>. The results indicate that the five price-related indicators demonstrate relatively consistent prediction accuracy and exhibit limited sensitivity to changes in input length. In contrast, trading volume presents significant variability. Owing to its high trading activity, pronounced volatility, and the absence of clear trends or structural stability, its prediction errors are notably sensitive to input sequence variations. Furthermore, to address the high degree of correlation among price-based features, each variable was modeled independently to evaluate changes in model performance when using only a single price indicator.</p>
<fig id="F11" position="float">
<label>Figure 11</label>
<caption><p>Comparison results of MSE, MAE, and MAPE for five key price indicators and trading volume across four different sequence length <italic>L</italic> &#x02208; {12, 36, 58, 96}.</p></caption>
<alt-text>Six bar charts showing different financial metrics (Low, Open, Volume, High, Close, Adj Close) across input sequence lengths (12, 36, 58, 96). Metrics include Mean Squared Error (MSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE), with varying bar heights indicating performance differences.</alt-text>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="frai-08-1599799-g0011.tif"/>
</fig>
</sec>
</sec>
<sec sec-type="conclusions" id="s6">
<title>6 Conclusions</title>
<p>In this study, we propose CMDMamba, an innovative dual-layer Mamba-based model that demonstrates exceptional hierarchical learning capabilities. The high-sensitivity branch precisely captures subtle fluctuations in financial markets, while the low-sensitivity branch focuses on modeling macro-trend dynamics. Leveraging Mamba&#x00027;s linear computational complexity, our framework significantly reduces operational costs without compromising performance. The DConvFFN module further enhances feature representation through temporal depth-wise convolution and cross-variable point-wise operations, achieving dynamic noise suppression and efficient extraction of multi-scale temporal patterns. Through comprehensive comparisons with various deep learning frameworks, we validate the potential of Mamba-based architectures for time series forecasting tasks.</p>
<p>Looking forward, future research will expand into multi-domain applications, particularly focusing on datasets with irregular patterns.CMDMamba not only overcomes the limitations of existing models in capturing the complexities of financial time series, but also delivers a more efficient and accurate solution for forecasting. With its innovative dual-layer Mamba architecture and DconvFFN module, CMDMamba achieves significantly improved prediction accuracy while preserving linear computational complexity. These advancements provide both a solid theoretical foundation and practical insights for future research and applications in financial time series forecasting. We are confident that continued optimization and functional enhancements will enable CMDMamba to achieve more remarkable results in cross-domain time series prediction. In summary, CMDMamba represents a significant advancement in financial time series forecasting. These findings not only underscore its robust efficacy but also highlight its substantial potential and broad application prospects in this critical field, laying a solid foundation for subsequent research and practical implementations.</p></sec>
</body>
<back>
<sec sec-type="data-availability" id="s7">
<title>Data availability statement</title>
<p>The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/supplementary material.</p>
</sec>
<sec sec-type="author-contributions" id="s8">
<title>Author contributions</title>
<p>ZQ: Formal analysis, Methodology, Writing &#x02013; original draft, Conceptualization, Investigation. BW: Methodology, Data curation, Investigation, Writing &#x02013; original draft, Software, Visualization. YZ: Validation, Investigation, Writing &#x02013; original draft, Methodology. ZL: Writing &#x02013; original draft, Resources, Project administration, Supervision, Writing &#x02013; review &#x00026; editing, Conceptualization, Investigation. XY: Validation, Supervision, Writing &#x02013; review &#x00026; editing, Conceptualization, Resources, Writing &#x02013; original draft, Formal analysis, Project administration. JJ: Writing &#x02013; review &#x00026; editing, Resources, Validation.</p>
</sec>
<sec sec-type="funding-information" id="s9">
<title>Funding</title>
<p>The author(s) declare that no financial support was received for the research and/or publication of this article.</p>
</sec>
<sec sec-type="COI-statement" id="conf1">
<title>Conflict of interest</title>
<p>The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
</sec>
<sec id="s10">
<title>Generative AI statement</title>
<p>The author(s) declare that no Gen AI was used in the creation of this manuscript.</p></sec>
<sec sec-type="disclaimer" id="s11">
<title>Publisher&#x00027;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p>
</sec>
<ref-list>
<title>References</title>
<ref id="B1">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ahamed</surname> <given-names>M. A.</given-names></name> <name><surname>Cheng</surname> <given-names>Q.</given-names></name></person-group> (<year>2024</year>). <article-title>&#x0201C;Timemachine: a time series is worth 4 mambas for long-term forecasting,&#x0201D;</article-title> in <source>ECAI 2024 27th European Conference on Artificial Intelligence, 19-24 October 2024, Santiago de Compostela, Spain - Including 13th Conference on Prestigious Applications of Intelligent Systems European Conference on Artificial Intelligence</source>, <fpage>1688</fpage>&#x02013;<lpage>1695</lpage>.<pub-id pub-id-type="pmid">39866204</pub-id></citation></ref>
<ref id="B2">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Behera</surname> <given-names>S.</given-names></name> <name><surname>Nayak</surname> <given-names>S. C.</given-names></name> <name><surname>Kumar</surname> <given-names>A. P.</given-names></name></person-group> (<year>2023</year>). <article-title>A comprehensive survey on higher order neural networks and evolutionary optimization learning algorithms in financial time series forecasting</article-title>. <source>Arch. Comp. Methods Eng</source>. <volume>30</volume>, <fpage>4401</fpage>&#x02013;<lpage>4448</lpage>. <pub-id pub-id-type="doi">10.1007/s11831-023-09942-9</pub-id></citation>
</ref>
<ref id="B3">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Behrouz</surname> <given-names>A.</given-names></name> <name><surname>Santacatterina</surname> <given-names>M.</given-names></name> <name><surname>Zabih</surname> <given-names>R.</given-names></name></person-group> (<year>2024a</year>). <article-title>Chimera: effectively modeling multivariate time series with 2dimensional state space models</article-title>. <source>arXiv preprint</source> arXiv:2406.04320.</citation>
</ref>
<ref id="B4">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Behrouz</surname> <given-names>A.</given-names></name> <name><surname>Santacatterina</surname> <given-names>M.</given-names></name> <name><surname>Zabih</surname> <given-names>R.</given-names></name></person-group> (<year>2024b</year>). <article-title>MambaMixer: efficient selective state space models with dual token and channel selection</article-title>. <source>arXiv</source> [preprint] arXiv:2403.19888. <pub-id pub-id-type="doi">10.48550/arXiv.2403.19888</pub-id></citation>
</ref>
<ref id="B5">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Chomicz-Grabowska</surname> <given-names>A. M.</given-names></name> <name><surname>Orlowski</surname> <given-names>L. T.</given-names></name></person-group> (<year>2020</year>). <article-title>Financial market risk and macroeconomic stability variables: dynamic interactions and feedback effects</article-title>. <source>J. Econ. Finance</source> <volume>44</volume>, <fpage>655</fpage>&#x02013;<lpage>669</lpage>. <pub-id pub-id-type="doi">10.1007/s12197-020-09505-9</pub-id></citation>
</ref>
<ref id="B6">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Das</surname> <given-names>A.</given-names></name> <name><surname>Kong</surname> <given-names>W.</given-names></name> <name><surname>Leach</surname> <given-names>A.</given-names></name> <name><surname>Mathur</surname> <given-names>S.</given-names></name> <name><surname>Sen</surname> <given-names>R.</given-names></name> <name><surname>Yu</surname> <given-names>R.</given-names></name></person-group> (<year>2023</year>). <article-title>Long-term forecasting with tide: time-series dense encoder</article-title>. <source>arXiv</source> [preprint] arXiv:2304.08424. <pub-id pub-id-type="doi">10.48550/arXiv.2304.08424</pub-id></citation>
</ref>
<ref id="B7">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ebrahimpour</surname> <given-names>R.</given-names></name> <name><surname>Nikoo</surname> <given-names>H.</given-names></name> <name><surname>Masoudnia</surname> <given-names>S.</given-names></name> <name><surname>Yousefi</surname> <given-names>M. R.</given-names></name> <name><surname>Ghaemi</surname> <given-names>M. S.</given-names></name></person-group> (<year>2011</year>). <article-title>Mixture of mlp-experts for trend forecasting of time series: A case study of the tehran stock exchange</article-title>. <source>Int. J. Forecast</source>. <volume>27</volume>, <fpage>804</fpage>&#x02013;<lpage>816</lpage>. <pub-id pub-id-type="doi">10.1016/j.ijforecast.2010.02.015</pub-id></citation>
</ref>
<ref id="B8">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Feng</surname> <given-names>F.</given-names></name> <name><surname>Huang</surname> <given-names>B.</given-names></name> <name><surname>Zhang</surname> <given-names>K.</given-names></name> <name><surname>Magliacane</surname> <given-names>S.</given-names></name></person-group> (<year>2022</year>). <article-title>Factored adaptation for non-stationary reinforcement learning</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>35</volume>, <fpage>31957</fpage>&#x02013;<lpage>31971</lpage>. <pub-id pub-id-type="doi">10.5555/3600270.3602586</pub-id></citation>
</ref>
<ref id="B9">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Ge</surname> <given-names>W.</given-names></name> <name><surname>Lalbakhsh</surname> <given-names>P.</given-names></name> <name><surname>Isai</surname> <given-names>L.</given-names></name> <name><surname>Lenskiy</surname> <given-names>A.</given-names></name> <name><surname>Suominen</surname> <given-names>H.</given-names></name></person-group> (<year>2022</year>). <article-title>Neural network-based financial volatility forecasting: a systematic review</article-title>. <source>ACM Comp. Surv</source>. <volume>55</volume>, <fpage>1</fpage>&#x02013;<lpage>30</lpage>. <pub-id pub-id-type="doi">10.1145/3483596</pub-id></citation>
</ref>
<ref id="B10">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Dao</surname> <given-names>T.</given-names></name></person-group> (<year>2023</year>). <article-title>Mamba: linear-time sequence modeling with selective state spaces</article-title>. <source>arXiv</source> [preprint] arXiv:2312.00752. <pub-id pub-id-type="doi">10.48550/arXiv.2312.00752</pub-id></citation>
</ref>
<ref id="B11">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Dao</surname> <given-names>T.</given-names></name> <name><surname>Ermon</surname> <given-names>S.</given-names></name> <name><surname>Rudra</surname> <given-names>A.</given-names></name> <name><surname>R&#x000E9;</surname> <given-names>C.</given-names></name></person-group> (<year>2020</year>). <article-title>Hippo: recurrent memory with optimal polynomial projections</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>33</volume>, <fpage>1474</fpage>&#x02013;<lpage>1487</lpage>.</citation>
</ref>
<ref id="B12">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>Gupta</surname> <given-names>A.</given-names></name> <name><surname>R&#x000E9;</surname> <given-names>C.</given-names></name></person-group> (<year>2022</year>). <article-title>On the parameterization and initialization of diagonal state space models</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>35</volume>, <fpage>35971</fpage>&#x02013;<lpage>35983</lpage>.</citation>
</ref>
<ref id="B13">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>R&#x000E9;</surname> <given-names>C.</given-names></name></person-group> (<year>2021a</year>). <article-title>Efficiently modeling long sequences with structured state spaces</article-title>. <source>arXiv</source> [preprint] arXiv:2111.00396. <pub-id pub-id-type="doi">10.48550/arXiv.2111.00396</pub-id></citation>
</ref>
<ref id="B14">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>R&#x000E9;</surname> <given-names>C.</given-names></name></person-group> (<year>2021b</year>). <article-title>Efficiently modeling long sequences with structured state spaces</article-title>. <source>arXiv</source> [preprint] arXiv:2111.00396.</citation>
</ref>
<ref id="B15">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>R&#x000E9;</surname> <given-names>C.</given-names></name></person-group> (<year>2021c</year>). <article-title>Efficiently modeling long sequences with structured state spaces</article-title>. <source>arXiv</source> [preprint] arXiv:2111.00396.</citation>
</ref>
<ref id="B16">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Johnson</surname> <given-names>I.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>Saab</surname> <given-names>K.</given-names></name> <name><surname>Dao</surname> <given-names>T.</given-names></name> <name><surname>Rudra</surname> <given-names>A.</given-names></name> <etal/></person-group>. (<year>2021d</year>). <article-title>Combining recurrent, convolutional, and continuous-time models with linear state space layers</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>34</volume>, <fpage>572</fpage>&#x02013;<lpage>585</lpage>.</citation>
</ref>
<ref id="B17">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Gu</surname> <given-names>A.</given-names></name> <name><surname>Johnson</surname> <given-names>I.</given-names></name> <name><surname>Goel</surname> <given-names>K.</given-names></name> <name><surname>Saab</surname> <given-names>K.</given-names></name> <name><surname>Dao</surname> <given-names>T.</given-names></name> <name><surname>Rudra</surname> <given-names>A.</given-names></name> <etal/></person-group>. (<year>2021e</year>). <article-title>Combining recurrent, convolutional, and continuous-time models with linear state space layers</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>34</volume>, <fpage>572</fpage>&#x02013;<lpage>585</lpage>.</citation>
</ref>
<ref id="B18">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Han</surname> <given-names>H.</given-names></name> <name><surname>Liu</surname> <given-names>Z.</given-names></name> <name><surname>Barrios Barrios</surname> <given-names>M.</given-names></name> <name><surname>Li</surname> <given-names>J.</given-names></name> <name><surname>Zeng</surname> <given-names>Z.</given-names></name> <name><surname>Sarhan</surname> <given-names>N.</given-names></name> <etal/></person-group>. (<year>2024</year>). <article-title>Time series forecasting model for non-stationary series pattern extraction using deep learning and garch modeling</article-title>. <source>J. Cloud Comp</source>. <volume>13</volume>:<fpage>2</fpage>. <pub-id pub-id-type="doi">10.1186/s13677-023-00576-7</pub-id></citation>
</ref>
<ref id="B19">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Hao</surname> <given-names>Y.</given-names></name> <name><surname>Gao</surname> <given-names>Q.</given-names></name></person-group> (<year>2020</year>). <article-title>Predicting the trend of stock market index using the hybrid neural network based on multiple time scale feature learning</article-title>. <source>Appl. Sci</source>. <volume>10</volume>:<fpage>3961</fpage>. <pub-id pub-id-type="doi">10.3390/app10113961</pub-id></citation>
</ref>
<ref id="B20">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Johnson</surname> <given-names>E.</given-names></name> <name><surname>Martinez</surname> <given-names>F.</given-names></name></person-group> (<year>2023</year>). <article-title>Sustainable energy solutions: Innovations and challenges</article-title>. <source>Heliyon</source> <volume>9</volume>:<fpage>e17847</fpage>.</citation>
</ref>
<ref id="B21">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Khan</surname> <given-names>M. A.</given-names></name> <name><surname>Khan</surname> <given-names>S. A.</given-names></name></person-group> (<year>2024</year>). <article-title>Explainable ai for time series forecasting: a survey</article-title>. <source>J. Big Data</source> <volume>11</volume>, <fpage>1</fpage>&#x02013;<lpage>34</lpage>.</citation>
</ref>
<ref id="B22">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Kingma</surname> <given-names>D. P.</given-names></name> <name><surname>Ba</surname> <given-names>J.</given-names></name></person-group> (<year>2014</year>). <article-title>Adam: A method for stochastic optimization</article-title>. <source>arXiv</source> [preprint] arXiv:1412.6980. <pub-id pub-id-type="doi">10.48550/arXiv.1412.6980</pub-id></citation>
</ref>
<ref id="B23">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Kitaev</surname> <given-names>N.</given-names></name> <name><surname>Kaiser</surname> <given-names>&#x00141;.</given-names></name> <name><surname>Levskaya</surname> <given-names>A.</given-names></name></person-group> (<year>2020</year>). <article-title>Reformer: the efficient transformer</article-title>. <source>arXiv</source> [preprint] arXiv:2001.04451. <pub-id pub-id-type="doi">10.48550/arXiv.2001.04451</pub-id></citation>
</ref>
<ref id="B24">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Kumar</surname> <given-names>A.</given-names></name> <name><surname>Lee</surname> <given-names>B.</given-names></name> <etal/></person-group>. (<year>2023</year>). <article-title>Business process management in the era of digital transformation</article-title>. <source>Bus. Process Manage. J</source>. <volume>30</volume>, <fpage>1716</fpage>&#x02013;<lpage>1736</lpage>. <pub-id pub-id-type="doi">10.1108/BPMJ-12-2023-0953</pub-id></citation>
</ref>
<ref id="B25">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Lara-Ben&#x000ED;tez</surname> <given-names>P.</given-names></name> <name><surname>Carranza-Garc&#x000ED;a</surname> <given-names>M.</given-names></name> <name><surname>Luna-Romera</surname> <given-names>J. M.</given-names></name> <name><surname>Riquelme</surname> <given-names>J. C.</given-names></name></person-group> (<year>2020</year>). <article-title>Temporal convolutional networks applied to energy-related time series forecasting</article-title>. <source>Appl. Sci</source>. <volume>10</volume>:<fpage>2322</fpage>. <pub-id pub-id-type="doi">10.3390/app10072322</pub-id></citation>
</ref>
<ref id="B26">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Li</surname> <given-names>S.</given-names></name> <name><surname>Jin</surname> <given-names>X.</given-names></name> <name><surname>Xuan</surname> <given-names>Y.</given-names></name> <name><surname>Zhou</surname> <given-names>X.</given-names></name> <name><surname>Chen</surname> <given-names>W.</given-names></name> <name><surname>Wang</surname> <given-names>Y.-X.</given-names></name> <etal/></person-group>. (<year>2019</year>). <article-title>Enhancing the locality and breaking the memory bottleneck of transformer on time series forecasting</article-title>. <source>arXiv</source> [preprint] arXiv:1907.00235. <pub-id pub-id-type="doi">10.48550/arXiv.1907.00235</pub-id></citation>
</ref>
<ref id="B27">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liang</surname> <given-names>A.</given-names></name> <name><surname>Jiang</surname> <given-names>X.</given-names></name> <name><surname>Sun</surname> <given-names>Y.</given-names></name> <name><surname>Shi</surname> <given-names>X.</given-names></name> <name><surname>Li</surname> <given-names>K.</given-names></name></person-group> (<year>2024</year>). <article-title>Bi-Mamba&#x0002B;: bidirectional mamba for time series forecasting</article-title>. <source>arXiv</source> [preprint] arXiv:2404.15772. <pub-id pub-id-type="doi">10.48550/arXiv.2404.15772</pub-id></citation>
</ref>
<ref id="B28">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname> <given-names>G.</given-names></name> <name><surname>Kim</surname> <given-names>H.</given-names></name></person-group> (<year>2025</year>). <article-title>Advancements in natural language processing: a review</article-title>. <source>Fronti. Artif. Intellig</source>. <volume>8</volume>:<fpage>1565287</fpage>.</citation>
</ref>
<ref id="B29">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname> <given-names>M.</given-names></name> <name><surname>Zeng</surname> <given-names>A.</given-names></name> <name><surname>Chen</surname> <given-names>M.</given-names></name> <name><surname>Xu</surname> <given-names>Z.</given-names></name> <name><surname>Lai</surname> <given-names>Q.</given-names></name> <name><surname>Ma</surname> <given-names>L.</given-names></name> <etal/></person-group>. (<year>2022a</year>). <article-title>Scinet: Time series modeling and forecasting with sample convolution and interaction</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>35</volume>, <fpage>5816</fpage>&#x02013;<lpage>5828</lpage>. <pub-id pub-id-type="doi">10.48550/arXiv.2106.09305</pub-id><pub-id pub-id-type="pmid">40363281</pub-id></citation></ref>
<ref id="B30">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname> <given-names>S.</given-names></name> <name><surname>Yu</surname> <given-names>H.</given-names></name> <name><surname>Liao</surname> <given-names>C.</given-names></name> <name><surname>Li</surname> <given-names>J.</given-names></name> <name><surname>Lin</surname> <given-names>W.</given-names></name> <name><surname>Liu</surname> <given-names>A. X.</given-names></name> <etal/></person-group>. (<year>2022b</year>). <article-title>&#x0201C;Pyraformer: low-complexity pyramidal attention for long-range time series modeling and forecasting,&#x0201D;</article-title> in <source>International Conference on Learning Representations (ICLR 2022), Virtual Conference (OpenReview)</source>.</citation>
</ref>
<ref id="B31">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname> <given-names>Y.</given-names></name> <name><surname>Hu</surname> <given-names>T.</given-names></name> <name><surname>Zhang</surname> <given-names>H.</given-names></name> <name><surname>Wu</surname> <given-names>H.</given-names></name> <name><surname>Wang</surname> <given-names>S.</given-names></name> <name><surname>Ma</surname> <given-names>L.</given-names></name> <etal/></person-group>. (<year>2023a</year>). <article-title>iTransformer: inverted transformers are effective for time series forecasting</article-title>. <source>arXiv</source> [preprint] arXiv:2310.06625. <pub-id pub-id-type="doi">10.48550/arXiv.2310.06625</pub-id></citation>
</ref>
<ref id="B32">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Liu</surname> <given-names>Y.</given-names></name> <name><surname>Hu</surname> <given-names>T.</given-names></name> <name><surname>Zhang</surname> <given-names>H.</given-names></name> <name><surname>Wu</surname> <given-names>H.</given-names></name> <name><surname>Wang</surname> <given-names>S.</given-names></name> <name><surname>Ma</surname> <given-names>L.</given-names></name> <etal/></person-group>. (<year>2023b</year>). <article-title>iTransformer: inverted transformers are effective for time series forecasting</article-title>. <source>arXiv</source> [preprint] arXiv:2310.06625.</citation>
</ref>
<ref id="B33">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Luo</surname> <given-names>Z.</given-names></name> <name><surname>Guo</surname> <given-names>W.</given-names></name> <name><surname>Liu</surname> <given-names>Q.</given-names></name> <name><surname>Zhang</surname> <given-names>Z.</given-names></name></person-group> (<year>2021</year>). <article-title>A hybrid model for financial time-series forecasting based on mixed methodologies</article-title>. <source>Expert Syst</source>. <volume>38</volume>:<fpage>e12633</fpage>. <pub-id pub-id-type="doi">10.1111/exsy.12633</pub-id></citation>
</ref>
<ref id="B34">
<citation citation-type="book"><person-group person-group-type="author"><name><surname>Markidis</surname> <given-names>S.</given-names></name> <name><surname>Der Chien</surname> <given-names>S. W.</given-names></name> <name><surname>Laure</surname> <given-names>E.</given-names></name> <name><surname>Peng</surname> <given-names>I. B.</given-names></name> <name><surname>Vetter</surname> <given-names>J. S.</given-names></name></person-group> (<year>2018</year>). <article-title>&#x0201C;NVIDIA tensor core programmability, performance &#x00026; precision,&#x0201D;</article-title> in <source>2018 IEEE international parallel and distributed processing symposium workshops (IPDPSW)</source> (<publisher-loc>Vancouver, BC</publisher-loc>: <publisher-name>IEEE</publisher-name>), <fpage>522</fpage>&#x02013;<lpage>531</lpage>.</citation>
</ref>
<ref id="B35">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Nguyen</surname> <given-names>K.</given-names></name> <name><surname>Chen</surname> <given-names>L.</given-names></name></person-group> (<year>2025</year>). <article-title>Human-AI collaboration: Enhancing productivity and creativity</article-title>. <source>Front. Artif. Intellig</source>. <volume>8</volume>:<fpage>1444891</fpage>.</citation>
</ref>
<ref id="B36">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Paszke</surname> <given-names>A.</given-names></name> <name><surname>Gross</surname> <given-names>S.</given-names></name> <name><surname>Massa</surname> <given-names>F.</given-names></name> <name><surname>Lerer</surname> <given-names>A.</given-names></name> <name><surname>Bradbury</surname> <given-names>J.</given-names></name> <name><surname>Chanan</surname> <given-names>G.</given-names></name> <etal/></person-group>. (<year>2019</year>). <article-title>PyTorch: An imperative style, high-performance deep learning library</article-title>. <source>arXiv</source> [preprint] arXiv.1912.01703. <pub-id pub-id-type="doi">10.48550/arXiv.1912.01703</pub-id></citation>
</ref>
<ref id="B37">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Patel</surname> <given-names>I.</given-names></name> <name><surname>Singh</surname> <given-names>J.</given-names></name></person-group> (<year>2023</year>). <article-title>Machine learning techniques in financial forecasting</article-title>. <source>J. Financ. Eng</source>. <volume>10</volume>:<fpage>3</fpage>.</citation>
</ref>
<ref id="B38">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Pokou</surname> <given-names>F.</given-names></name> <name><surname>Sadefo Kamdem</surname> <given-names>J.</given-names></name> <name><surname>Benhmad</surname> <given-names>F.</given-names></name></person-group> (<year>2024</year>). <article-title>Hybridization of arima with learning models for forecasting of stock market time series</article-title>. <source>Comp. Econ</source>. <volume>63</volume>, <fpage>1349</fpage>&#x02013;<lpage>1399</lpage>. <pub-id pub-id-type="doi">10.1007/s10614-023-10499-9</pub-id><pub-id pub-id-type="pmid">38478502</pub-id></citation></ref>
<ref id="B39">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Qin</surname> <given-names>Z.</given-names></name> <name><surname>Wei</surname> <given-names>B.</given-names></name> <name><surname>Gao</surname> <given-names>C.</given-names></name> <name><surname>Chen</surname> <given-names>X.</given-names></name> <name><surname>Zhang</surname> <given-names>H.</given-names></name> <name><surname>In Wong</surname> <given-names>C. U.</given-names></name></person-group> (<year>2025</year>). <article-title>Sfdformer: a frequency-based sparse decomposition transformer for air pollution time series prediction</article-title>. <source>Front. Environm. Sci</source>. <volume>13</volume>:<fpage>1549209</fpage>. <pub-id pub-id-type="doi">10.3389/fenvs.2025.1549209</pub-id></citation>
</ref>
<ref id="B40">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Salinas</surname> <given-names>D.</given-names></name> <name><surname>Flunkert</surname> <given-names>V.</given-names></name> <name><surname>Gasthaus</surname> <given-names>J.</given-names></name> <name><surname>Januschowski</surname> <given-names>T.</given-names></name></person-group> (<year>2020</year>). <article-title>Deepar: Probabilistic forecasting with autoregressive recurrent networks</article-title>. <source>Int. J. Forecast</source>. <volume>36</volume>, <fpage>1181</fpage>&#x02013;<lpage>1191</lpage>. <pub-id pub-id-type="doi">10.1016/j.ijforecast.2019.07.001</pub-id><pub-id pub-id-type="pmid">33375148</pub-id></citation></ref>
<ref id="B41">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Sezer</surname> <given-names>O. B.</given-names></name> <name><surname>Gudelek</surname> <given-names>M. U.</given-names></name> <name><surname>Ozbayoglu</surname> <given-names>A. M.</given-names></name></person-group> (<year>2020</year>). <article-title>Financial time series forecasting with deep learning: a systematic literature review: 2005-2019</article-title>. <source>Appl. Soft Comput</source>. <volume>90</volume>:<fpage>106181</fpage>. <pub-id pub-id-type="doi">10.1016/j.asoc.2020.106181</pub-id></citation>
</ref>
<ref id="B42">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Shehzad</surname> <given-names>K.</given-names></name> <name><surname>Xiaoxing</surname> <given-names>L.</given-names></name> <name><surname>Kazouz</surname> <given-names>H.</given-names></name></person-group> (<year>2020</year>). <article-title>Covid-19&#x00027;s disasters are perilous than global financial crisis: a rumor or fact?</article-title> <source>Finance Res. Letters</source> <volume>36</volume>, <fpage>101669</fpage>&#x02013;<lpage>101669</lpage>. <pub-id pub-id-type="doi">10.1016/j.frl.2020.101669</pub-id><pub-id pub-id-type="pmid">32837374</pub-id></citation></ref>
<ref id="B43">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Smith</surname> <given-names>L.</given-names></name> <name><surname>Doe</surname> <given-names>J.</given-names></name></person-group> (<year>2024</year>). <article-title>Ethical considerations in ai-powered decision making</article-title>. <source>Front. Artif. Intellig</source>. <volume>7</volume>:<fpage>1290491</fpage>.</citation>
</ref>
<ref id="B44">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Song</surname> <given-names>Y.</given-names></name> <name><surname>Cai</surname> <given-names>C.</given-names></name> <name><surname>Ma</surname> <given-names>D.</given-names></name> <name><surname>Li</surname> <given-names>C.</given-names></name></person-group> (<year>2024</year>). <article-title>Modelling and forecasting high-frequency data with jumps based on a hybrid nonparametric regression and lstm model</article-title>. <source>Expert Syst. Appl</source>. <volume>237</volume>:<fpage>121527</fpage>. <pub-id pub-id-type="doi">10.1016/j.eswa.2023.121527</pub-id></citation>
</ref>
<ref id="B45">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Torres</surname> <given-names>J. F.</given-names></name> <name><surname>Hadjout</surname> <given-names>D.</given-names></name> <name><surname>Sebaa</surname> <given-names>A.</given-names></name> <name><surname>Mart&#x000ED;nez-&#x000C1;lvarez</surname> <given-names>F.</given-names></name> <name><surname>Troncoso</surname> <given-names>A.</given-names></name></person-group> (<year>2021</year>). <article-title>Deep learning for time series forecasting: a survey</article-title>. <source>Big Data</source> <volume>9</volume>, <fpage>3</fpage>&#x02013;<lpage>21</lpage>. <pub-id pub-id-type="doi">10.1089/big.2020.0159</pub-id><pub-id pub-id-type="pmid">33275484</pub-id></citation></ref>
<ref id="B46">
<citation citation-type="book"><person-group person-group-type="author"><name><surname>Triantafyllopoulos</surname> <given-names>K.</given-names></name></person-group> (<year>2021</year>). <article-title>&#x0201C;The state space model in finance,&#x0201D;</article-title> in <source>Bayesian Inference of State Space Models: Kalman Filtering and Beyond</source> (<publisher-loc>Cham</publisher-loc>: <publisher-name>Springer International Publishing</publisher-name>), <fpage>341</fpage>&#x02013;<lpage>402</lpage>.</citation>
</ref>
<ref id="B47">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wang</surname> <given-names>Z.</given-names></name> <name><surname>Kong</surname> <given-names>F.</given-names></name> <name><surname>Feng</surname> <given-names>S.</given-names></name> <name><surname>Wang</surname> <given-names>M.</given-names></name> <name><surname>Yang</surname> <given-names>X.</given-names></name> <name><surname>Zhao</surname> <given-names>H.</given-names></name> <etal/></person-group>. (<year>2025</year>). <article-title>Is mamba effective for time series forecasting?</article-title> <source>Neurocomputing</source> <volume>619</volume>:<fpage>129178</fpage>. <pub-id pub-id-type="doi">10.1016/j.neucom.2024.129178</pub-id><pub-id pub-id-type="pmid">39866204</pub-id></citation></ref>
<ref id="B48">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wu</surname> <given-names>H.</given-names></name> <name><surname>Xu</surname> <given-names>J.</given-names></name> <name><surname>Wang</surname> <given-names>J.</given-names></name> <name><surname>Long</surname> <given-names>M.</given-names></name></person-group> (<year>2021</year>). <article-title>Autoformer: decomposition transformers with auto-correlation for long-term series forecasting</article-title>. <source>Adv. Neural Inf. Process. Syst</source>. <volume>34</volume>, <fpage>22419</fpage>&#x02013;<lpage>22430</lpage>.</citation>
</ref>
<ref id="B49">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Wu</surname> <given-names>Y.</given-names></name> <name><surname>Wang</surname> <given-names>S.</given-names></name> <name><surname>Fu</surname> <given-names>X.</given-names></name></person-group> (<year>2024</year>). <article-title>Long short-term temporal fusion transformer for short-term forecasting of limit order book in china markets</article-title>. <source>Appl. Intellig</source>. <volume>54</volume>, <fpage>12979</fpage>&#x02013;<lpage>13000</lpage>. <pub-id pub-id-type="doi">10.1007/s10489-024-05789-0</pub-id></citation>
</ref>
<ref id="B50">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Yao</surname> <given-names>Y.</given-names></name> <name><surname>yang Zhang</surname> <given-names>Z.</given-names></name> <name><surname>Zhao</surname> <given-names>Y.</given-names></name></person-group> (<year>2023</year>). <article-title>Stock index forecasting based on multivariate empirical mode decomposition and temporal convolutional networks</article-title>. <source>Appl. Soft Comput</source>. <volume>142</volume>:<fpage>110356</fpage>. <pub-id pub-id-type="doi">10.1016/j.asoc.2023.110356</pub-id></citation>
</ref>
<ref id="B51">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Yu</surname> <given-names>Y.</given-names></name> <name><surname>Kuang</surname> <given-names>G.</given-names></name> <name><surname>Zhu</surname> <given-names>J.</given-names></name> <name><surname>Shen</surname> <given-names>L.</given-names></name> <name><surname>Wang</surname> <given-names>M.</given-names></name></person-group> (<year>2024</year>). <article-title>Long-term interbank bond rate prediction based on iceemdan and machine learning</article-title>. <source>IEEE Access</source>. <volume>12</volume>, <fpage>46241</fpage>&#x02013;<lpage>46262</lpage>. <pub-id pub-id-type="doi">10.1109/ACCESS.2024.3381500</pub-id></citation>
</ref>
<ref id="B52">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Zeng</surname> <given-names>A.</given-names></name> <name><surname>Chen</surname> <given-names>M.</given-names></name> <name><surname>Zhang</surname> <given-names>L.</given-names></name> <name><surname>Xu</surname> <given-names>Q.</given-names></name></person-group> (<year>2023</year>). <article-title>Are transformers effective for time series forecasting?</article-title> <source>Proc. AAAI Conf. Artif. Intellig</source>. <volume>37</volume>, <fpage>11121</fpage>&#x02013;<lpage>11128</lpage>. <pub-id pub-id-type="doi">10.1609/aaai.v37i9.26317</pub-id></citation>
</ref>
<ref id="B53">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Zeng</surname> <given-names>P.</given-names></name> <name><surname>Hu</surname> <given-names>G.</given-names></name> <name><surname>Zhou</surname> <given-names>X.</given-names></name> <name><surname>Li</surname> <given-names>S.</given-names></name> <name><surname>Liu</surname> <given-names>P.</given-names></name> <name><surname>Liu</surname> <given-names>S.</given-names></name></person-group> (<year>2022</year>). <article-title>Muformer: A long sequence time-series forecasting model based on modified multi-head attention</article-title>. <source>Knowl.-Based Syst</source>. <volume>254</volume>:<fpage>109584</fpage>. <pub-id pub-id-type="doi">10.1016/j.knosys.2022.109584</pub-id></citation>
</ref>
<ref id="B54">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Zhang</surname> <given-names>C.</given-names></name> <name><surname>Wang</surname> <given-names>D.</given-names></name></person-group> (<year>2024</year>). <article-title>Remote sensing applications in urban planning: A case study</article-title>. <source>Remote Sens</source>. <volume>16</volume>, <fpage>2620</fpage>. <pub-id pub-id-type="doi">10.3390/rs16142620</pub-id></citation>
</ref>
<ref id="B55">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Zhang</surname> <given-names>L.</given-names></name> <name><surname>Hua</surname> <given-names>L.</given-names></name></person-group> (<year>2025</year>). <article-title>Major issues in high-frequency financial data analysis: a survey of solutions</article-title>. <source>Mathematics</source> <volume>13</volume>:<fpage>347</fpage>. <pub-id pub-id-type="doi">10.3390/math13030347</pub-id></citation>
</ref>
<ref id="B56">
<citation citation-type="journal"><person-group person-group-type="author"><name><surname>Zhou</surname> <given-names>H.</given-names></name> <name><surname>Zhang</surname> <given-names>S.</given-names></name> <name><surname>Peng</surname> <given-names>J.</given-names></name> <name><surname>Zhang</surname> <given-names>S.</given-names></name> <name><surname>Li</surname> <given-names>J.</given-names></name> <name><surname>Xiong</surname> <given-names>H.</given-names></name> <etal/></person-group>. (<year>2021</year>). <article-title>Informer: Beyond efficient transformer for long sequence time-series forecasting</article-title>. <source>Proc. AAAI conf. Artif. Intellig</source>. <volume>35</volume>, <fpage>11106</fpage>&#x02013;<lpage>11115</lpage>. <pub-id pub-id-type="doi">10.1609/aaai.v35i12.17325</pub-id></citation>
</ref>
<ref id="B57">
<citation citation-type="book"><person-group person-group-type="author"><name><surname>Zhou</surname> <given-names>T.</given-names></name> <name><surname>Ma</surname> <given-names>Z.</given-names></name> <name><surname>Wen</surname> <given-names>Q.</given-names></name> <name><surname>Wang</surname> <given-names>X.</given-names></name> <name><surname>Sun</surname> <given-names>L.</given-names></name> <name><surname>Jin</surname> <given-names>R.</given-names></name></person-group> (<year>2022</year>). <article-title>&#x0201C;FEDformer: Frequency enhanced decomposed transformer for long-term series forecasting,&#x0201D;</article-title> in <source>International Conference on Machine Learning</source> (<publisher-loc>New York</publisher-loc>: <publisher-name>PMLR</publisher-name>), <fpage>27268</fpage>&#x02013;<lpage>27286</lpage>.<pub-id pub-id-type="pmid">37107476</pub-id></citation></ref>
</ref-list>
</back>
</article> 