Words that shake traders. The stock market's reaction to central bank communication in real time

This paper investigates the effects of Federal Reserve's decisions and statements on U.S. stock and volatility indices (Dow Jones Industrial Average, NASDAQ 100, S&P 500, and VIX) using a high-frequency event-study analysis. I find that both the surprise component of policy actions and official communication have statistically significant and economically relevant effects on equity indices, with statements having a much greater explanatory power of the reaction of stock prices to monetary policy. For instance, around 90% of the explainable variation in S&P 500 is due to the surprise component of Fed's statements. This paper also shows that equity indices tend to incorporate FOMC monetary surprises within 40. min from the announcement release. Finally, I find that these results are robust along several dimensions. In particular, I consider different estimators, such as the Generalized Empirical Likelihood, and I extend the sample to include the recent period of heightened financial stress. This sensitivity analysis corroborates that central bank communication about its future policy intentions is a key driver of stock returns. © 2011 Elsevier B.V