What explains short-term ‡uctuations of stock prices? This paper exploits a natural experiment from the 18 th century in which information ‡ows were regularly interrupted for exogenous reasons. English shares were traded on the Amsterdam exchange and news came in on sailboats that were often delayed because of adverse weather conditions. The paper documents that prices responded strongly to boat arrivals, but there was considerable volatility in the absence of news. The evidence suggests that this was largely the result of the revelation of (long-lived) private information and the (transitory) impact of uninformed liquidity trades on intermediaries'risk premia.JEL Codes: G14, N2 Keywords: asset price volatility, news, liquidity, …nancial history Stanford University and NBER. This paper is based on the …rst chapter of my dissertation. I thank Hans-Joachim Voth (advisor), and Fernando Broner and Jaume Ventura (committee members) for their advice and support. I thank