US shares rose strongly on Thursday as bargain hunters picked up cheap stocks following three days of falls, BBC reports.
Despite continuing signs that the global economy is sliding into recession, Wall Street's main Dow Jones index ended up 523 points or 6.7%.
The rise came in the face of another increase in US unemployment, Wal-Mart warning of weaker festive sales and Intel issuing a profit warning.
And car giant Chrysler said it may not survive without a government bail-out.
Despite such a mass of gloomy news, the Nasdaq index also advanced strongly, gaining 6.5%.
Ryan Larson, senior equity trader at Voyageur Asset Management, blamed the "herd mentality" for the big share price rises.
"We started going higher - and you don't want to be the last one on the boat."
Other analysts suggested some investors were more optimistic ahead of this weekend's Group of 20 gathering of world leaders in Washington.
The meeting aims to look at further ways to help the global financial sector get back to normal, and combat signs of global recession.
US President George W Bush said the meeting would look at practical measures but that there was nothing fundamentally wrong with a market-led economy.