S&P 500 Snapshot: A Modest Gain On Weak Investor Participation By: TalkMarkets August 23, 2016 at 17:56 PM EDT The S&P 500 rallied at the open and hit its 0.49% intraday high about 30 minutes into the session. Read More >> Related Stocks: SPDR S&P 500 ETF Trust Standard & Poors 500