Since 1930, the S&P 500 (NYSEARCA:SPY) has traded a grand total of 148 Friday 13th across all twelve months.
The overall track record is 80 up days and 68 down (or unchanged) days with a bearish average loss of 0.04%. The worst Friday 13th loss was 6.12% in October 1989. This day is often referred to as “Black Friday.” Digging deeper into the data reveals that this upcoming April Friday 13th has been down (or unchanged) six times, up three times with an average gain of 0.02%. Median performance is a loss of 0.15%. Depending on which metric chosen, November is either the worst or in a virtual tie for worst month for Friday 13th. October has a similar average loss, but with two additional up days. June is the best month for Friday 13th, up 11 times in 13 with an average gain of 0.55%.