US stocks slumped Thursday on European debt concerns and bearish US economic data, with the Dow index tumbling more than three percent for its biggest drop in more than a year. The Dow Jones Industrial Average fell 376.36 points (3.60 percent) to 10,068.01, its third straight day of losses and biggest percentage fall since March 5 last year.
The tech-rich Nasdaq composite fell 94.36 points (4.11 percent) to 2,204.01 while the broad-market Standard & Poor's 500 shed 43.46 points (3.90 percent) to 1,071.59.
All 30 of the Dow's blue-chip components closed lower, with Bank of America and aluminum producer Alcoa recording the steepest daily drops.
Wall Street remain gripped by the eurozone debt crisis but local factors fueled the fresh stock plunge.
Fresh government data showed the largest number of Americans lining up for unemployment insurance claims in five weeks while a private survey indicated that the US economic recovery could stall.
A bill to overhaul financial rules and clean up Wall Street also passed a key hurdle Thursday in Congress, a victory for President Barack Obama but a blow to the corporate barons on Wall Street.
"With traders already on edge amid ongoing turmoil in the eurozone, the day's questionable economic reports pushed the remaining bulls over the brink," said analyst Elizabeth Harrow of Schaeffer's Investment Research.
"By the close, the Dow was clinging to the 10,000 level for dear life," she said.
Oil prices in New York also dived Thursday to near 10-month lows.
New claims for US unemployment benefits have risen for the first time in five weeks, official data showed Thursday.
The Labor Department said initial jobless claims totaled 471,000 in the week ending May 15, up 25,000 or 5.6 percent from the prior week's revised figure of 446,000.
The figure was higher than the average analyst forecast of a drop to 439,000 new claims.
Analysts at Charles Schwab & Co said stock investors were concerned about the drop for the first time in nearly a year of a key index tracking the US economy.
The 0.1 percent decline in the forward-looking leading economic index (LEI) in April was the first decline since March 2009 -- following a 1.3 percent gain in March and a 0.4 percent rise in February.
"These latest results suggest a recovery that will continue through the summer, although it could lose a little steam," said Ken Goldstein, economist at The Conference Board.
Alcoa was down 6.03 percent to 11.07 dollars and Bank of America slipped 6.19 percent to 15.30 dollars.
Construction equipment giant Caterpillar shed 4.51 percent to 58.67 dollars while industrial behemoth General Electric lost 5.79 percent to 16.26 dollars.
The bond market surged as investors took refuge in US Treasuries. The yield on the 10-year US Treasury bond decreased to 3.264 percent from 3.359 percent a day earlier while that on the 30-year bond slipped to 4.135 percent from 4.237 percent. Bond prices and yields move in opposite directions.
