Researcher ORCID Identifier

0009-0006-0526-906X

Graduation Year

2026

Date of Submission

4-2026

Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts

Department

Economics

Reader 1

Darren Filson

Abstract

This paper examines whether AI keyword mentions in quarterly earnings reports (10-Qs) are associated with abnormal returns, and whether this effect differs across technology and non-technology firms (SIC codes 7370-7379) and pre- and post-ChatGPT release in November 2022. I examine 4,898 quarterly earnings announcements by S&P 500 firms from March 2022 - December 2024. Cumulative abnormal returns (CARs) are calculated using the Fama-French 5-factor model, controlling for earning surprise. AI mentions are associated with a mean CAR that is 0.76 percentage points higher, (CÂR = 0.0076, p < .01), suggesting a positive short-run market response to AI disclosure. However, once pre/post-ChatGPT period effects are controlled for, the AI mention effect weakens and loses statistical significance (CÂR = 0.0049, p > .10). The interaction between AI mentions and the post-ChatGPT period indicator is also insignificant (β = 0.0003, p > .10). Overall, there is no statistically significant evidence that ChatGPT’s release amplified the market’s response to AI mentions in either tech or non-tech firms. However, tech firms mentioning AI earn significantly higher CARs than non-tech firms mentioning AI, with a premium of approximately 3.3 percentage points (β = 0.0327, p < .05), providing support for industry heterogeneity. The main conclusion is that markets reward AI mentions more for technology firms, but do not systematically reward it more following ChatGPT’s release.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.

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