The tech-rich Nasdaq Composite Index tumbled more than two percent in midday trade Friday in a sell-off that battered most of the sector. Around 1730 GMT, the Nasdaq sank 96.85 points (2.29 percent) to 4,140.89, near the session low of 4,131.03. The big drop came after the Department of Labor reported the US economy added 192,000 jobs in March, essentially meeting expectations and suggesting a continuation of the trend of slow but steady improvement in the recovery labor market. But analysts said the sell-off was spurred not by the jobs report or other news, but by the same negative sentiment that has hit tech and biotech names intermittently over the last two weeks or so. A recurring concern is that hot technology stocks like Facebook and Netflix are overvalued. "It's all been momentum," said Michael James, managing director of equity trading at Wedbush Securities. "As the stocks go lower and continue to go lower, portfolio managers have to react. They may not want to be selling stocks, but they can't allow this to keep going." Big drops came at Amazon (-4.7 percent), Google (-3.2 percent), Facebook (-4.0 percent), Netflix (-4.5 percent) and Biogen (-3.7 percent). Apple, the tech titan, lost 1.2 percent. The broader market also fell, but not as much. The Dow Jones Industrial Average lost 81.75 (0.49 percent) to 16,490.80, while the broad-based S&P 500 shed 15.77 (0.83 percent) at 1,873.00.