Best and worst months

Conventional wisdom pegs October as the worst month of the year for the stock market. It was in that month that the crashes of 1929 and 1987 occurred.

But that wisdom is wrong: September has proved to be the worst month of the year, with the worst record over the past 50 years. The Standard & Poor’s 500 Index has lost an average of 0.52% in September over that period, worse than any month.

The most recent September-October period offered an extreme example. The S&P 500 lost 10.87% in September, the worst showing of any month in 2002. Meanwhile, October turned out to be the best month of the year, with a gain of 8.8%. This monthly gain occurred despite a big decline through October 9, when the stock market hit its lowest point so far in the bear market.