S&P 500 was down 8.2% in May 2010, which is the worst monthly performance since February of 2009.
SPX was down more than 5% in a month 63 times since January 1950. In 33 out of 63 cases, the following month was negative for the index. On the graph above you may see the distribution of 5% down months. December had only one occasion where SPX was down more than 5%.
