A street sign is seen in front of an American flag hanging on the front of the New York Stock Exchange...
A street sign is seen in front of an American flag hanging on the front of the New York Stock Exchange August 9, 2007. U.S. stocks tumbled on Thursday, with the Dow and S&P down nearly 3 percent, after a French bank froze three funds that invested in U.S. subprime mortgages, prompting central banks to take steps to calm investors. REUTERS/Lucas Jackson (UNITED STATES)