Today is the first day of September. No matter how you look at it, September has been an awful month for the U.S. stock market, and has been for more than a century.
Since the Dow Jones Industrial Average was created in the late 1890s, September has produced an average loss of 1.1 percent. The 11 other months of the calendar, in contrast, have produced an average gain of 0.8 percent.
Furthermore, September has an impressively consistent record at or near the bottom of the rankings. September was a below-average performer in all but one of the dozen decades since the late 1800s. And in more than half of those decades, it was in 11th or 12th place in a ranking of monthly average performance.