(with Mirko S. Heinle and Christopher S. Armstrong)
Review of Accounting Studies (2024), forthcoming
Standard Bayesians' beliefs converge when they receive the same piece of new information. However, when agents have uncertainty about the precision of a signal, their beliefs might instead diverge more despite receiving the same information. We demonstrate that this divergence leads to a unimodal effect of the absolute surprise in the signal on trading volume. We show that this prediction is consistent with the empirical evidence using trading volume around earnings announcements of US firms. We find evidence of elevated volume following moderate surprises and depressed volume following more extreme surprises, a pattern that is more pronounced when investors are more uncertain about earnings' precision. Because investors can disagree even further after receiving the same piece of news, the relationship between news and trading volume is not necessarily linear, suggesting that trading volume may not be an appropriate proxy for market liquidity.