From Bias to Behavior: Learning Bull-Bear Market Dynamics with Contrastive Modeling

TL;DR

This paper introduces B4, a contrastive model that captures the dynamic interplay of biases and behaviors in financial markets, improving trend prediction and offering interpretability of market regimes.

Contribution

The paper presents a novel contrastive framework that jointly models price sequences and external signals to understand bias-driven market dynamics, a departure from prior approaches.

Findings

B4 outperforms existing models in trend prediction accuracy.

The model provides interpretable insights into market bias and behavioral divergence.

Experimental results validate the effectiveness of the proposed approach.

Abstract

Financial markets exhibit highly dynamic and complex behaviors shaped by both historical price trajectories and exogenous narratives, such as news, policy interpretations, and social media sentiment. The heterogeneity in these data and the diverse insight of investors introduce biases that complicate the modeling of market dynamics. Unlike prior work, this paper explores the potential of bull and bear regimes in investor-driven market dynamics. Through empirical analysis on real-world financial datasets, we uncover a dynamic relationship between bias variation and behavioral adaptation, which enhances trend prediction under evolving market conditions. To model this mechanism, we propose the Bias to Behavior from Bull-Bear Dynamics model (B4), a unified framework that jointly embeds temporal price sequences and external contextual signals into a shared latent space where opposing bull and bear forces naturally emerge, forming the foundation for bias representation. Within this space, an inertial pairing module pairs temporally adjacent samples to preserve momentum, while the dual competition mechanism contrasts bullish and bearish embeddings to capture behavioral divergence. Together, these components allow B4 to model bias-driven asymmetry, behavioral inertia, and market heterogeneity. Experimental results on real-world financial datasets demonstrate that our model not only achieves superior performance in predicting market trends but also provides interpretable insights into the interplay of biases, investor behaviors, and market dynamics.