In a punishing week for the market, the main indexes fell sharply as record-high crude oil prices and a sagging dollar further undermined sentiment.
The Dow Jones Industrial Average tumbled 4.07 percent in the week to Friday to end at 13.042.74.
The broad market Standard & Poor's 500 slid 3.7 percent to 1,453.70 and the tech-heavy Nasdaq plummeted 6.5 percent to 2,627.94 amid a sharp shift in sentiment on technology companies like Google and Apple.
Markets have been getting more bad news from the financial sector all week starting with a shakeup at Citigroup as the US banking titan said it would have to write off up to 11 billion dollars in soured real-estate investments, far higher than earlier anticipated.
Other banks also warned of writedowns including Wachovia, Bank of America and JP Morgan Chase.
"The major hurdle for the market has been and will continue to be the fate of the financials," said Larry Wachtel at Wachovia Securities.
Wachtel said the market fears "s