The Greenspan Years : An Analysis of the Magnitude and Speed of the Equity Market Response to FOMC Announcements

We examine the impact of monetary policy on the Samp;P 500 using intraday data. The analysis shows an economically and statistically significant relationship between Samp;P 500 intraday returns and changes in the Fed funds target rate. The significance and magnitude of the response is dependent on whether the change was expected or unexpected. An expected change in the Fed funds target rate has no impact on prices in the broad equity market; however, an unexpected change of 25 basis points in the Fed funds target rate results in an approximate 48 basis points decline in the broad equity market's return. The speed of these market reactions is rapid with the equity market reaching a new equilibrium within 15 minutes