Dynamic Asset Pricing: Integrating FinBERT-Based Sentiment Quantification with the Fama--French Five-Factor Model
Chi Zhang
TL;DR
This study addresses how time-varying sentiment derived from FinBERT can be integrated into asset pricing. It develops a daily sentiment index $S_t$ and its volatility $HV_t$, and embeds them into the Fama–French five-factor model, including an interaction with $HV_t$ to capture regime shifts, evaluated via rolling regressions and event studies around major shocks such as the June 15, 2022 Fed rate hike. The results show sentiment has a positive effect on returns in normal periods but can reverse or amplify under high uncertainty, with rolling Coefficients $\,\hat{\gamma}_w$ indicating strong time variation and conditional relevance. An event study demonstrates the sentiment-augmented model better explains abnormal returns around policy announcements, supporting the usefulness of NLP-derived sentiment in real-time asset pricing and its potential applications for investors and regulators.
Abstract
This paper presents a comprehensive study on the integration of text-derived, time-varying sentiment factors into traditional multi-factor asset pricing models. Leveraging FinBERT, a domain-specific deep learning language model, we construct a dynamic sentiment index and its volatility from large-scale financial news and social media data covering 2020 to 2022. By embedding these sentiment measures into the Fama French five-factor regression, we rigorously examine whether sentiment significantly explains variations in daily stock returns and how its impact evolves across different market volatility regimes. Empirical results demonstrate that sentiment has a consistently positive impact on returns during normal periods, while its effect is amplified or even reversed under extreme market conditions. Rolling regressions reveal the time-varying nature of sentiment sensitivity, and an event study around the June 15, 2022 Federal Reserve 75 basis point rate hike shows that a sentiment-augmented five-factor model better explains abnormal returns relative to the baseline model. Our findings support the incorporation of high-frequency, NLP-derived sentiment into classical asset pricing frameworks and suggest implications for investors and regulators.
