Strong summer end often leads to stock market turbulence in early fall

There may be some cloudy days ahead for the stock market after the strong summer run. The S & P 500 is on pace to end August 2% higher after rising 2.2% in July. The benchmark is also on pace for its fourth straight monthly advance. But the index typically averages a 0.7% decline in September, making it the worst month of the year historically, according to the Stock Trader's Almanac. With the S & P 500's July and August rallies, September could bring even rougher waters based on historical patterns. Looking only at years when the broad index gained more than 2% in both July and August, that average September slide increases to 1%. Of those 11 years going back to 1949, all but three have ended in the red. Additionally, seven of those 11 years had a negative October. The average loss for th