Stocks ended flat after volatile trading Thursday ahead of the widely watched government jobs report, with the Dow and S&P 500 retreating from record intraday highs earlier in the session.
The Nasdaq closed down nearly 1 percent, dragged by declines in momentum and biotech stocks.
The Global X Social Media ETF, which includes Facebook, LinkedIn and Groupon, dropped more than 3 percent. The Nasdaq biotechnology index also slid 3 percent. Momentum stocks including Tesla, Netflix and Priceline were also in the red as investors took profits from recent gains.
The Dow Jones Industrial Average bobbed in and out of positive territory. The blue-chip index earlier rose to set its first record high of 2014.
The S&P 500 hovered around the flatline. The CBOE Volatility Index (VIX), widely considered the best gauge of fear in the market, traded near 13.
Among key S&P sectors, materials gained, while health care sagged.
Investors also seemed hesitant to make big bets ahead of the monthly government jobs report due Friday. Economists polled by Reuters expect a gain of 197,000 new jobs in March. The U.S. created 175,000 jobs in February, exceeding expectations.
On the economic front, weekly jobless claims gained more than expected last week, increasing 16,000 to a seasonally adjusted 326,000, according to the Labor Department.
Growth in the services sector accelerated in March, with the Institute for Supply Management saying its service sector index rose to 53.1 in March, slightly below expectations for a reading of 53.5 but ahead of the February read of 51.6.
Meanwhile, the U.S. trade deficit unexpectedly widened 7.7 percent to $42.3 billion in February, according to the Commerce Department as exports fell to their lowest level in five months, further signs economic growth slowed in the first quarter.