The S&P 500 has done very well on days when the Federal Reserve's policymaking committee has met, a Tuesday report from Bespoke Investment Group found.
Bespoke said the index has averaged a gain of 0.34 percent on Fed days since 1995, which is about 10 times better than its average daily percentage gain on every other trading day over that same period.
"While just 3% of all trading days have been Fed Days since 1995, roughly 35% of the market's gain over this time has come from Fed Days," according to Bespoke. The firm also found that, if investors had owned only the S&P on Fed days since 1995, $100 would be $178. Had investors owned the index on all trading days other than Fed days, $100 would be $260.
Source: Bespoke Investment Group
That said, the S&P fell 0.12 percent and 0.18 percent on the past two Fed days. "While the S&P did little on the June and July Fed Days, that's a time of year when markets are historically very slow," Bespoke said. "September and October have historically been the most volatile months of the year, and September has historically been the worst month of the year for markets as well."