Source: Ecker, Li Y., Li X. & Wu (2025) — “How Stock Market Participants Use Generative Artificial Intelligence: Evidence from User-Platform Interaction Data”
I like finance papers that accidentally become papers about human behaviour. This one does that. It looks like a study about data, markets, or disclosure, but underneath it is really about how people decide what to believe.
We’ve been talking about how investors might use AI for investment research. This paper has actual data on how they do use it — and the picture is more nuanced than the hype would suggest. Using a dataset of 1.7 million stock-related queries submitted to one of China’s largest GenAI platforms during the first half of 2024, the researchers document what users are asking and how usage patterns vary. The query data covers a wide range of topics and task types, and importantly, it comes with metadata on user sophistication and usage intensity. First, query activity increases substantially around corporate disclosure events — earnings announcements, major news. This confirms the intuition that investors are using AI to process specific information at specific moments, not just for general research. Second, these increases in query activity largely track contemporaneous media coverage of the same events. Users appear to be asking AI about things they’re also reading about elsewhere, rather than using it as a primary discovery channel. Third, and most interesting to me: there’s evidence of substitution. More sophisticated users and heavier users query differently — they use AI for more complex, analytical tasks rather than simple factual lookups.
My takeaway: AI and data do not remove judgment from finance. They move judgment to the part where people decide what the signal means, whether it is trustworthy, and whether they are brave enough to act on it.