What A Difference A Day Makes: The Calendar Roll

 | Aug 23, 2016 01:44AM ET

The S&P 500 Index was essentially flat today, down .06%; however, an investor's one year price only return will increase over three full percentage points from last Friday's close to today's close. For an investor invested in the S&P 500 Index, Friday's (8/19/2016) one year price only return equaled 7.28% and one day forward to Monday's close, the investor's one year return increases to 10.74%. The reason for this is the calendar rolling forward one day, weekends result in some nuances, and August of last year was a volatile month to the down side for the market and this is contributing to the magnitude of the change in return.