The Release of GPT-4 and Trading Activity in U.S. Equity Markets
This paper analyzes changes in U.S. stock market trading activity around the release of GPT-4 in March 2023. We use a segmented interrupted time-series design with level-discontinuity and regression-kink components. The analysis uses monthly market-wide trading data from March 2020 to May 2026 and supplementary FINRA m...