Below are the seasonality stats for the S&P 500 during the Summer months:
- June: Higher 65% of the time in the last 20yrs. Avg % return = 0% (Yes you read that right, 0% is the average return for June)
- July: Higher 45% of the time in the last 20yrs. Avg % return = +0.4%
- August: Higher 55% of the time in the last 20yrs. Avg % return = -0.8%
(Seasonality data from equityclock.com)
I find it interesting that the only month with a positive average historical return (July) was the one in which had the lowest probability of having a positive returns.