Euro-zone fears rattle U.S. stocks; Pfizer climbs By: MarketWatch May 04, 2010 at 09:48 AM EDT U.S. stocks opened broadly lower Tuesday, pushing the Dow Jones Industrial Average below the key 11,000 level as worries over euro-zone debt returned. Read More >> Related Stocks: Alcoa Apple Merck & Co Pearson Plc ADR Pfizer Standard & Poors 500