September has a history of being the worst month of the year for the stock market, according to a report from Steven C. Leuthold of the Leuthold Group.
While October has a reputation for dramatic declines, 54% of Octobers since 1900 have been up months, said the report, citing figures from Ned Davis Research.
"The odds are pretty good that September 1996 will be a significant down month," the report said. "The inability of the stock market to score a gain on the Friday before the Labor Day weekend (most unusual) may be an omen."