which has been the worst month for stocks historically 
that depends on the time period you look at over the past century september has been the worst performing month for stocks losing around 1 on average 3the bottom linethe october effect is the belief that stocks fall on average during the month of october this supposed market anomaly has been cited in reflection of large market crashes that have occurred during this month such as 1987 s black monday however actual evidence for the october effect is scant and in fact october has been a net positive month on average going back a century for example october of 2022 was one of the best performing months in recent stock market history as with other supposed market anomalies the reality is that they probably don t exist as markets do tend to be efficient especially once anomalies are identified and publicly known as such one probably should not use the notion of the october effect to make trading decisions 