This week is options expiration week and mid-August is usually better performing than the beginning and the end of the month.
This strength is punctuated with a three-day string of bullish days running from Thursday August 15 until August 19. A bullish day is defined as a trading day in which the S&P 500 (NYSEARCA:SPY) has risen greater than or equal to 60% of the time over the past 21 years. Unfortunately, this bullish cluster has not always resulted in full-week gains during option expiration nor does this daily bullish streak guarantee market gains on each day. DJIA(NYSEARCA:DIA) and S&P 500 have declined on August option expiration day seven times in the last nine years and have suffered full-week losses in six of the last nine August expiration weeks.