U.S. stocks extend gains on stress tests By: MarketWatch March 14, 2012 at 09:14 AM EDT U.S. stocks start out Wednesday slightly higher, spillover buying in the wake of largely positive results from stress tests for the nation’s biggest banks. Read More >> Related Stocks: American Express Apple Bank of America Citigroup JPMorgan Chase & Co MetLife Standard & Poors 500 SunTrust Banks U.S. Bancorp