1. Introduction
The digital finance revolution has fundamentally restructured economic interactions, introducing cryptocurrencies not merely as alternative payment systems but as a distinct asset class characterized by decentralized infrastructure and algorithmic governance [
1,
2]. Since the inception of Bitcoin in 2008 as a response to systemic financial fragility, the ecosystem has expanded exponentially. By late 2025, over 9000 cryptocurrencies were actively traded globally, underscoring a massive shift in capital allocation driven by technological innovation and investor demand [
3]. However, unlike traditional equities or fiat currencies, which are anchored by macroeconomic fundamentals and cash flows, digital assets exhibit chaotic volatility clustering, non-stationary pricing dynamics, and heavy-tailed distributions.
These stochastic characteristics present a formidable challenge for predictive modeling. The absence of fundamental valuation anchors renders cryptocurrency prices highly susceptible to speculative sentiment, information dispersion, and market microstructure noise. Consequently, classical econometric approaches and linear time-series methods frequently fail to capture the abrupt regime shifts and nonlinear dependencies inherent in this domain [
4,
5]. In response to these limitations, the forecasting literature has aggressively pivoted toward Machine Learning (ML) and Deep Learning (DL) architectures [
6,
7]. Prevailing bibliometric data indicate a consensus that advanced algorithms—capable of modeling high-dimensional relationships—offer superior efficacy compared to traditional benchmarks [
8].
Specifically, the field has seen a surge in the application of Recurrent Neural Networks (RNNs), such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) models [
9]. These architectures are explicitly designed to handle temporal dependencies and have demonstrated localized success in cryptocurrency markets [
10,
11]. Concurrently, various studies have proposed hybrid ensembles and decomposition-based frameworks to further enhance predictive accuracy [
12,
13,
14,
15,
16,
17,
18,
19]. However, this “rush to complexity” has created an epistemological gap: does increasing algorithmic sophistication systematically yield robust predictive performance in high-entropy environments?
While some literature champions the use of complex hybrid models [
14,
20], other evidence suggests that simpler, asset-specific specifications may offer better generalization [
21,
22]. This uncertainty points to a potential “Complexity–Performance Paradox,” where over-parameterized deep learning models risk fitting stochastic noise rather than the underlying deterministic trend, particularly in assets prone to extreme volatility. Furthermore, the “black box” nature of deep networks exacerbates the trade-off between accuracy and interpretability [
23,
24]. For predictive models to be actionable for risk managers and policymakers, they must be transparent. Although Explainable AI (XAI) methods like SHapley Additive exPlanations (SHAP) have emerged to address this, their application in comparative crypto forecasting remains limited and fragmented [
25,
26].
This study addresses these unresolved issues by revisiting the Principle of Parsimony (Occam’s Razor) in cryptocurrency forecasting. We posit that simpler, robust algorithms may outperform complex deep architectures when market volatility disrupts neural network gradients. To test this, we employ a multi-asset framework encompassing Bitcoin (BTC), Ethereum (ETHUM), Binance Coin (BNB), Solana (SOLU), and Ripple (XRP), which represent heterogeneous liquidity and volatility regimes [
27,
28,
29,
30].
Methodologically, we contrast the performance of sequence-learning models (LSTM, GRU) with that of kernel-based Shallow Learning, specifically Support Vector Machines (SVM). While LSTM and GRU are adept at capturing long-term dependencies [
31], SVM operates on the principle of Structural Risk Minimization (SRM), which, in theory, offers superior resistance to overfitting in high-dimensional spaces compared to Empirical Risk Minimization (ERM), often used in neural networks [
32]. By integrating these models with SHAP analysis, this study challenges the “deeper is better” narrative and aims to provide a transparent, regime-sensitive forecasting framework.
Accordingly, this research is guided by the following questions:
RQ1. Do ML and DL models differ significantly in out-of-sample forecasting accuracy across cryptocurrencies with heterogeneous liquidity and volatility profiles?
RQ2. Does increased model complexity and hybridization systematically lead to superior predictive performance, or does it succumb to the “Complexity–Performance Paradox”?
RQ3. Which technical indicators and price-based features exert the strongest influence on model predictions as identified through SHAP-based interpretability analysis?
RQ4. Are the predictive drivers and model stability consistent across different cryptocurrencies and volatility regimes?
The remainder of this paper is organized as follows:
Section 2 reviews the relevant literature on ML and DL in crypto forecasting.
Section 3 details the data, feature engineering, and methodological framework.
Section 4 presents empirical results and SHAP analysis.
Section 5 discusses the implications of the findings and concludes the study.
5. Discussion and Conclusions
In this study, we revisited the efficacy of computational forecasting techniques in the cryptocurrency domain through a rigorous comparative evaluation of ML and DL models. Rather than relying solely on in-sample fit—a metric often inflated by overfitting—this analysis emphasized out-of-sample predictive accuracy, algorithmic stability across heterogeneous volatility regimes, and the interpretability of decision boundaries. By jointly assessing forecasting outcomes and SHAP-based explanations, the paper offers direct responses to the research questions outlined in the introduction. It challenges the prevailing “complexity bias” in the existing literature. In addition, structural break and stationarity tests were conducted to ensure that latent structural changes in the data did not drive the empirical results.
Addressing RQ1, which asks, “
Do ML and DL models differ significantly in out-of-sample forecasting accuracy across cryptocurrencies with heterogeneous liquidity and volatility profiles?”, the empirical results yield a definitive response. We observe a substantial divergence in model performance dictated by asset-specific volatility dynamics. Contrary to the assumption that deep architectures are inherently superior, the parsimonious SVM model consistently outperformed LSTM and GRU networks in assets characterized by extreme volatility and structural breaks, such as Bitcoin and Ripple. This outperformance is robust across all error metrics, suggesting that SVM provides greater forecast stability during sudden price movements. DL approaches, conversely, tend to exhibit advantages only when price dynamics evolve smoothly, and temporal dependence is the dominant factor. These findings align with evidence reported by [
6,
32,
40], refuting the universality of DL superiority in crypto markets.
Regarding RQ2, which investigates, “
Does increased model complexity and hybridization systematically lead to superior predictive performance, or does it succumb to the ‘Complexity–Performance Paradox’?”, our data indicate that the paradox is real. We find no systematic evidence that increased complexity enhances accuracy in high-entropy environments. The complex GRU + LSTM hybrid architecture notably underperformed simpler single-model specifications in highly volatile assets. This suggests that stacking recurrent layers can amplify noise rather than signal, leading to overfitting and weakened out-of-sample robustness when regime shifts occur frequently—consistent with [
7,
44]. A conditional exception was observed for Solana, where the LSTM + SVM hybrid delivered strong performance. This nuance indicates that hybridization is only beneficial when model design is tailored to asset-specific liquidity and volatility characteristics, supporting the asset-based perspectives of [
14,
16].
Turning to RQ3, concerning “
Which technical indicators and price-based features exert the strongest influence on model predictions as identified through SHAP-based interpretability analysis?”, the SHAP results provide a clear hierarchy. Across all configurations, immediate price-related variables—specifically Volume-Weighted Average Price, daily High, and Opening price—dominate the prediction mechanism, particularly in SVM-based models. Technical indicators occupy a secondary role; their explanatory power is limited in isolation and becomes meaningful only when combined with core price variables. This finding is consistent with prior evidence reported by [
25,
63], and it supports the argument that short-term momentum and volatility dynamics play a central role in cryptocurrency price formation [
28]. While ref. [
59] demonstrates that incorporating Twitter sentiment, news sentiment, and socio-economic variables alongside Bitcoin prices markedly improves altcoin directional accuracy, the SHAP-based evidence of the present study reveals that, within a purely price-based technical feature set, instantaneous price variables consistently dominate secondary indicators. This complementary finding suggests that the marginal contribution of external sentiment signals may be context-dependent and asset-specific.
Lastly, RQ4 addresses, “
Are the predictive drivers and model stability consistent across different cryptocurrencies and volatility regimes?” The results reveal significant heterogeneity. While core price variables remain universally important, the directional influence and relative weight of technical indicators vary markedly across assets and volatility regimes. This instability reflects differences in market maturity, liquidity depth, and trading behavior, confirming that cryptocurrency markets are not homogeneous [
27,
29].
Beyond statistical significance, the empirical findings carry important economic implications for cryptocurrency markets. The relatively strong performance of SVM models in highly volatile assets such as BTC and XRP suggests that simpler machine learning approaches may deliver more reliable forecasting signals under turbulent market conditions. For investors and portfolio managers, this implies that simpler models may yield more stable predictions during periods of sharp price fluctuations, thereby improving portfolio allocation and risk management decisions. In contrast, deep learning models such as LSTM and GRU tend to perform better under calmer market dynamics, where temporal dependencies dominate price movements. This finding indicates that the economic value of forecasting models depends substantially on prevailing market conditions rather than on algorithmic complexity alone [
6].
Furthermore, the dominance of price-based variables identified through SHAP analysis underscores that short-term price formation in cryptocurrency markets is driven primarily by instantaneous price dynamics rather than secondary technical indicators. From an economic standpoint, this finding suggests that investors and analysts should prioritize core price variables when constructing forecasting frameworks or trading strategies. From a regulatory and market surveillance perspective, the results demonstrate that cryptocurrency markets exhibit heterogeneous dynamics across assets, implying that risk assessment and monitoring frameworks should account for asset-specific liquidity and volatility characteristics when evaluating market stability.
Taken together, the results demonstrate that algorithmic complexity does not guarantee predictive superiority. In assets prone to frequent regime shifts, parsimonious SVM architectures deliver superior stability relative to DL models. The empirical success of SVM supports the principle of SRM over the ERM paradigm commonly associated with neural networks. While DL models excel at stationary pattern recognition tasks, their performance deteriorates in non-stationary financial environments. SVM’s ability to control the upper bound of generalization error renders it more robust to the stochastic noise inherent in cryptocurrency markets—an interpretation supported by [
98,
99,
100].
The findings provide several practical implications for investors, analysts, risk managers, and policymakers. From a portfolio management perspective, the results indicate that model selection should account for market regimes and asset-specific volatility characteristics rather than relying solely on increasingly complex deep learning architectures. In highly volatile market conditions, simpler machine learning approaches such as Support Vector Machines (SVM) tend to provide more robust and stable forecasting performance. In contrast, during relatively stable market phases where price dynamics evolve more smoothly, deep learning architectures such as LSTM and GRU may offer stronger predictive capabilities. This regime-aware modeling perspective suggests that effective forecasting frameworks should remain flexible and volatility-sensitive, a conclusion consistent with previous evidence in the literature [
101,
102].
From a broader market and regulatory perspective, the results also reveal that cryptocurrency markets exhibit heterogeneous dynamics across different assets, reflecting variations in liquidity, volatility, and structural characteristics. These differences imply that risk assessment and market monitoring frameworks should incorporate asset-specific features when evaluating market stability. Consequently, both portfolio management strategies and regulatory surveillance systems may benefit from adopting analytical frameworks that explicitly account for volatility regimes and cross-asset heterogeneity.
Despite these contributions, several limitations should be acknowledged. First, the analysis focuses on a limited number of major cryptocurrencies—BTC, BNB, ETHUM, SOLU, and XRP—which may restrict the generalizability of the findings to smaller or less liquid digital assets. Second, the empirical analysis relies on daily data covering the 2020–2025 period; therefore, the results may partly reflect the specific market conditions, structural shifts, and heightened volatility episodes observed during this timeframe. Third, although the study evaluates multiple machine learning and deep learning models, it does not encompass all potential forecasting architectures or alternative feature engineering strategies that may influence predictive performance. In addition, the analysis primarily focuses on forecasting accuracy and model interpretability, while other practical considerations—such as real-time trading implementation, portfolio optimization, and transaction costs—remain outside the scope of the current framework.
Another limitation relates to the explanatory variables used in the models. The present study relies exclusively on price-based technical indicators and does not incorporate sentiment signals from social media platforms or broader macroeconomic variables. Previous research suggests that integrating such information sources can improve directional prediction accuracy in cryptocurrency markets [
59]. Incorporating these additional features within the proposed regime-sensitive modeling framework represents a promising direction for future research.
Future research may extend this framework by including longer historical datasets, including lower-liquidity cryptocurrencies, and testing alternative hybrid forecasting architectures. Additionally, adopting regime-switching or real-time forecasting frameworks could provide further insights into model robustness under rapidly changing market conditions and enhance the practical applicability of cryptocurrency forecasting systems.
In conclusion, the findings suggest that effective cryptocurrency forecasting depends less on methodological complexity and more on regime sensitivity and asset-specific dynamics. The results demonstrate that (i) machine learning and deep learning models exhibit significant differences in out-of-sample performance, (ii) increasing model complexity does not necessarily improve predictive accuracy and may sometimes reduce it, (iii) price-based indicators remain dominant predictors, and (iv) the effects of explanatory variables vary across both assets and volatility regimes. Accordingly, cryptocurrency forecasting should adopt a dynamic, asset-aware, and volatility-sensitive modeling perspective rather than defaulting to increasingly complex predictive architectures.