Stocks slide as energy, Pfizer weigh By: MarketWatch May 03, 2011 at 09:56 AM EDT U.S. stocks fell Tuesday, deepening losses after the opening bell, as Pfizer’s revenues disappointed investors at the tail end of a generally positive earnings season. Read More >> Related Stocks: AT&T Inc Avon Products Ford Motor General Motors MasterCard Pfizer Standard & Poors 500 Verizon Communications