The S&P 500 is sitting on a relatively small gain of 2% so far in 2015. Interestingly, though, the index has only been up on 46% of trading days so far this year. And only two days of the week have averaged gains — Monday and Thursday.
Below is a chart showing the average performance of the S&P 500 by weekday so far this year. As shown, the S&P has averaged a gain of 0.21% on Mondays and +0.47% on Thursdays, while it has averaged declines on Tuesdays, Wednesdays and Fridays.
In terms of consistency, Thursday has been the day to be invested in the market, with positive returns 64% of the time. Mondays have seen gains 58% of the time. For bears out there, Wednesday has been the day that the market has struggled, with positive returns just 29% of the time.
We obviously wouldn’t base an investment thesis around day of the week, but it is interesting to note the pretty wide performance discrepancies that we’ve seen so far this year.