10 stocks hard at work during summer vacation By: CNBC.com News September 02, 2014 at 14:26 PM EDT As Wall Street returns back to work, these S&P 500 stocks were busy all summer making big returns in investors' portfolios. Read More >> Related Stocks: Coach Genworth Financial Harley-Davidson Intel Corp Mattel Michael Kors Holdings Nike Inc PetSmart, Inc. Sentinelone Inc Cl A Under Armour