Abstract
This dissertation studies biases on both sides of modern financial markets---those of human investors and those of the machine-learning tools increasingly used to study them. The first chapter identifies a textual property of news---narrative unpredictability---through which investors can overcome the bias-prone, heuristic (System~1) default of news processing, finding that the cognitive strain it induces can pull investors into slower, more deliberate (System~2) analysis and thereby attenuate market underreaction. The second chapter, which provides the methodological infrastructure that makes such a study credible, develops chronologically consistent large language models that are free of lookahead bias---a measurement-side bias whose mitigation supports more credible backtests and predictions across finance and other social-science domains. The third chapter turns to a different human bias---racial bias in capital allocation by mutual fund managers---documenting a co-racial tilt in portfolio choices consistent with inaccurate statistical discrimination, together with an asymmetric investor response in which minority-dominant funds are penalized similarly to White-dominant funds for poor performance but not rewarded as much for superior performance. Taken together, the three chapters trace bias in financial markets across three distinct layers: the bias-prone System~1 default through which investors process news, the measurement-side distortions of the language models used to study them, and the race-related tilts shaping how professional capital allocators direct capital across firms.
Committee Chair
Asaf Manela
Committee Members
Andreas Neuhierl; Brett Green; Guofu Zhou; Xing Huang
Degree
Doctor of Philosophy (PhD)
Author's Department
Finance
Document Type
Dissertation
Date of Award
5-5-2026
Language
English (en)
DOI
https://doi.org/10.7936/rcp3-vd37
Recommended Citation
Wu, Jimmy, "Essays in Human and Machine Biases in Financial Markets" (2026). Olin Business School Graduate Student Theses and Dissertations. 68.
The definitive version is available at https://doi.org/10.7936/rcp3-vd37