US STOCKS-S&P 500 posts biggest weekly decline since 2012 By: Reuters: Company News August 01, 2014 at 16:40 PM EDT * Indexes down: Dow 0.4 pct, S&P 0.3, Nasdaq 0.4 pct (Updates to close) Read More >> Related Stocks: Gopro Inc Cl A Procter & Gamble Scientific Games Tesla, Inc.