September Returns: Sinister Market Seasonality Statistics

 | Sep 06, 2017 12:49AM ET

For southern hemisphere dwellers such as myself, September brings spring, but for the S&P 500 September brings sinister seasonal statistics. Over the period 1964-2016 September has been the month with the worst average return (average -0.4% m/m) and the lowest probability of a positive return (returns were positive for the month 'only' 45% of the time). With a long list of potential concerns e.g. North Korea, government shutdown, super storms, high valuations, low cash holdings, other factors it tends to make you pay attention.

Looking across the 1964-2016 period, September has seen the worst average monthly price performance.