US STOCKS-Wall St falls, Nasdaq under 50-day moving average
* Ukraine conflict continues; Russia seizes marine base
* Weak China data raises hopes for stimulus
* Nasdaq hit as Internet, biotech names tumble
* Herbalife rallies, Icahn to get more reps on board
* Dow off 0.4 pct; S&P 500 down 0.7 pct; Nasdaq off 1.7 pct (Updates to early afternoon)
By Ryan Vlastelica
NEW YORK, March 24 (Reuters) - U.S. stocks fell sharply on Monday, with the Nasdaq marking its biggest daily percentage drop since early February as some of the market's recent best performers like technology and biotech shares led the way down.
Concerns that the crisis in Ukraine could escalate pushed traders to drop some of the market's biggest trading favorites, taking the Nasdaq below its 50-day moving average in a sign of weakening near-term momentum.
Almost 80 percent of the stocks traded on the Nasdaq were lower, while about two-thirds of New York Stock Exchange-listed shares fell. Eight of the 10 S&P 500 sectors slid for the day. Continuación...