第八讲 AI (ChatGPT) Democratization and Trading Inequality

时间：2025年 05月20日 周二 北京时间 下午14:00-15:30

地点/Venue：

线下：北京大学国家发展研究院承泽园校区132教室

线上：ZOOM会议（会议号: 897 2560 1400  密码: 938759）

主讲人/Speaker:    Xiumin Martin

主持人/Host：       胡佳胤 Jiayin Hu

摘要/Abstract:

We present the first analysis of the influence of democratized AI’s (ChatGPT) on investors’ trading activities. We develop an AI-sentiment measure using earnings conference calls. We find that before the introduction of ChatGPT, short-selling activities exhibited alignment with AI-sentiment, whereas retail trading did not. However, following the wide deployment of ChatGPT, we observed a significant increase in the AI alignment of retail traders, accompanied by a decrease in the alignment of short sellers, implying that AI contributes to reducing the trading inequality between retail investors and short sellers. We further find that the primary mechanism driving the AI democratization effect on retail trading is its ability to lower information processing costs for retail investors. Lastly, AI-sentiment positively predicts returns both before and after the democratization of AI in a similar way, with no subsequent return reversal observed in the long run. This evidence suggests that AI-sentiment effectively captures fundamental information, and the increased alignment of retail investors’ trading with AI-sentiment does not appear to have a measurable impact on price efficiency. To strengthen our causal inferences, we examined the impact of exogenous ChatGPT outages. These outages significantly reduced the alignment between retail and AI-sentiment, thus reinforcing our conclusions.

 主讲人介绍/Biography:

Xiumin Martin is a Professor of Accounting at Olin Business School, Washington University in St. Louis. Her areas of expertise are financial accounting, financial reporting, and corporate governance. Her research focuses on the role of financial information in the capital market in promoting debt contracting efficiency and improving the efficiency of asset allocation. She has published extensively in top-tier academic journals, including The Accounting Review, Journal of Accounting and Economics, Journal of Finance, Journal of Financial Economics, and Management Science. 

Professor Martin served as an Editor at The Accounting Review between 2017-2023, and is an Associate Editor at Management Science since 2021. She joined Olin Business School in 2007 after graduating from the University of Missouri in Columbia. Before her work towards her doctorate degree Professor Martin worked at Deloitte and Touche Tohmatsu in Shanghai as an Auditor.