Wall Street stocks rallied on Tuesday after a dizzying two-week slide. Trading was volatile and accelerated into the close of the session.
The S&P 500 posted its best day in more than two years, following a drop of nearly 17% over the past weeks.
The market reversed direction six times after the US Federal reserve pledged two more years of interest rates at almost zero.
The Dow Jones Index rose 430 points, or 4%, to close at 11,240.
The Nasdaq Composite rose 125 points, or 5.3%, to finish at 2483.
Standard & Poor's 500 Index rose 53.07 points, or 4.74%, to 1,172.
About 16.4 billion shares were traded on the New York Stock Exchange, NYSE Amex and Nasdaq - more than twice the daily average so far this year.
European shares also recovered heavy losses made in a volatile morning's trading.
Some indexes, like the FTSE 100 in London, that fell by up to 5.5% on Monday, were positive by the time Wall Street opened. The FTSE closed up 1.89% at 5,164.92.
In Paris the CAC-40 gained 1.63% to close at 3,176.19 and the DAX in Frankfurt ended nearly flat with a drop of 0.10% to 5,917.08.