Sell on Rosh Hashanah, Buy on Yom Kippur

According to CNBC’s Turney Duff, it’s an article of faith at many trading desks that the Jewish New Year, Rosh Hashanah, is the time to sell. The Jewish calendar functions differently than the 12-month calendar, so Rosh Hashanah doesn’t happen on the same day every year. Keeping a Jewish calendar handy will help gentiles keep the timing straight, and they’ll also need it a couple of weeks later when Yom Kippur rolls around, the Jewish day of atonement. According to the superstition, that's the time to buy.

Duff said that this trade works “more often than not,” and there’s solid data to back it up. According to the Wall Street Journal, the S&P 500 index has had an average decline of half a percentage point during the seven or eight trading days that typically take place during Rosh Hashanah and Yom Kippur, going back as far as 1971. At the same time, that period in 2008 saw the S&P 500 drop 17.8%, so your mileage may vary.