US STOCKS-Nasdaq ends below 4,000 for first time since early Feb.
* Momentum, biotech stocks take another plunge
* S&P 500, Nasdaq post worst weekly decline since June 2012
* Dow down 0.9 pct; S&P 500 off 1 pct; Nasdaq down 1.3 pct (Updates to close)
By Angela Moon
NEW YORK, April 11 (Reuters) - U.S. stocks slid in a volatile session on Friday, with the Nasdaq closing below the 4,000 mark for the first time since early February.
Selling accelerated late in the afternoon, with the biotech and other momentum stocks again leading the Nasdaq sharply lower. JPMorgan's disappointing earnings also gave investors a reason to sell some bank stocks.
For the week, the S&P 500 fell 2.6 percent and the Nasdaq lost 3.1 percent, the biggest weekly decline for both indexes since June 2012.
"Today's decline is what we've been seeing all week. The weakness in the biotech and momentum names is getting investors worried about where the market is headed in the near-term, eventually triggering a selloff in everything," said Robert Pavlik, chief market strategist at Banyan Partners in New York.
"Our long-term outlook on the market hasn't changed because if you understand why the market is selling off, you know it's not rational, that it doesn't make sense," he added. Continuación...