| NEW YORK
NEW YORK Stocks surged to multi-year highs on Thursday after the Federal Reserve announced an aggressive plan to stimulate the economy, encouraging investors to dive back into the market.
The Dow and the S&P 500 both closed at their highest levels since December 2007, while the Nasdaq ended at the highest since November 2000.
Major market names were big winners, with Apple Inc (AAPL.O), the most valuable U.S. company, ending at an all-time closing high and No. 2 Exxon Mobil (XOM.N), closing at a four-year high. Nearly 600 shares on the New York Stock Exchange and Nasdaq touched 52-week highs on the day.
"There has been a lot of money that's been sitting on the sidelines, and the Fed action is what spurred people to get in," said Tim Ghriskey, chief investment officer at Solaris Asset Management in Bedford Hills, New York. "The spike in volume is certainly heartening."
Total volume was 8.14 billion shares, the busiest day of trading since June 22 and above last year's daily average of 7.84 billion.
In a significant shift in monetary policy, the Fed said it would buy $40 billion of agency mortgage debt per month and pledged to maintain it until the U.S. unemployment rate, currently at 8.1 percent, significantly improves.
"The employment situation ... remains a grave concern," Fed Chairman Ben Bernanke told reporters. "While the economy appears to be on a path of moderate recovery, it isn't growing fast enough to make significant progress reducing the unemployment rate."
The Dow Jones industrial average .DJI ended up 206.51 points, or 1.55 percent, to 13,539.86. The Standard & Poor's 500 Index .SPX closed up 23.43 points, or 1.63 percent, to 1,459.99. The Nasdaq Composite Index .IXIC rose 41.51 points, or 1.33 percent, to 3,155.83.
Financial, materials and energy shares led the gains given their sensitivity to the economic outlook. Wells Fargo (WFC.N) jumped to a new 52-week high while the PHLX Housing Index .HGX rose 1.91 percent.
The buying of mortgage bonds is "very positive for the housing market, and for consumers in general and should really go a long way to helping stabilize the economy," Ghriskey said.
Many investors had expected the Fed to act, as reflected in the latest run-up in equity prices, but analysts said there were still some who believed that the Fed would wait until after the November presidential election.
"A lot of those doubters had to be brought up to speed here, so to speak," said Ron Rowland, president of Capital Cities Asset Management in Austin, Texas.
In an additional move that reflects just how concerned Fed officials are about the economy, officials said they were not likely to raise interest rates from near zero until at least mid-2015. Previously, it had set such guidance at late 2014.
Apple's stock (AAPL.O) rose 1.97 percent to $682.98 after analysts said sales of the new iPhone 5 could double those of the previous model in its first week on the market.
Exxon Mobil (XOM.N) gained 1.88 percent to $91.23.
The S&P financial sector index .GSPF added 2.58 percent. The S&P materials sector index .GSPM advanced 2.56 percent.
Some analysts said with the S&P 500 index up 16 percent since the beginning of the year and stocks' recent advance on hopes for help from central banks, the gains may be an opportunity for investors to pare positions.
Economic data showed the number of Americans filing new claims for jobless benefits rose more than expected last week. Wholesale prices rose 1.7 percent in August, the largest gain since June 2009, although core inflation was stable.
On the New York Stock Exchange, about four stocks rose for every one that fell. On the Nasdaq, five stocks rose for every two that fell.
(Editing by Kenneth Barry)