The Federal Open Market Committee (FOMC) is the monetary policy-making body of the U.S. Federal Reserve System. Since 1981 the FOMC has had eight scheduled meetings per year, the timing of which is quite irregular, The schedule of meetings for a particular year is announced ahead of time [calendar here].
Starting in 1994, the FOMC began to issue a policy statement (“FOMC statement”) after the meetings that summarised the Committee’s economic outlook and the policy decision at that meeting. The FOMC statements are released around 14h15 Eastern Time.
Before 1994 monetary policy decisions were not announced; investors therefore had to guess policy actions from the size and type of open market operations in the days following each meeting. But since 1994 there has been far greater transparency over both the timing and the motivation for monetary policy actions.
This has led to a number of academic papers investigating the influence of these FOMC statements on financial markets. One such paper found large average excess returns on U.S. equities in the 24-hour period immediately before the announcements (an effect the paper called the “Pre-FOMC Announcement Drift”). In other words, equities tended to be strong just before the FOMC statement. Further, these excess returns have increased over time and they account for sizable fractions of total annual realized stock returns. Quantifying this the paper says,
[since 1994] the S&P500 index has on average increased 49 basis points in the 24 hours before scheduled FOMC announcements. These returns do not revert in subsequent trading days and are orders of magnitude larger than those outside the 24-hour pre-FOMC window. As a result, about 80% of annual realized excess stock returns since 1994 are accounted for by the pre-FOMC announcement drift
A quite extraordinary finding!
And the relevance to UK equities is…?
The above quoted paper also found that such pre-FOMC excess returns occurred also in major international equity indices.
Let’s see if that is the case.
The following chart shows the average daily returns for the FTSE 100 Index for the seven days around the FOMC statements for the period 1994-2014. The seven days cover the three days leading up to the statement, the day of the statement itself A(0), and the then the three days after the statement. Given that the FOMC statement is usually released around 18h15 GMT (i.e. after the UK market has closed), A(0) can be taken as occurring in the 24 hours before the statement.
The result is quite clear, the average daily return for A(0) is 0.33%, over ten times greater than the average daily return on all other days. This does support the claim in the above referenced paper. It might also be interesting to note the weakness in equities on the day prior to the FOMC statement.
 David O. Lucca, Emanuel Moench, “The Pre-FOMC Announcement Drift” (2013)
Further articles on the Fed Rate and FOMC announcements.