The tech-rich Nasdaq Composite Index Thursday led US stocks sharply lower as anxiety about pricey technology equities returned with a vengeance and dragged down the broader market. The Nasdaq tumbled 129.79 points (3.10 percent) to 4,054.11. The Dow Jones Industrial Average sank 266.96 (1.62 percent) to 16,170.22, while the broad-based S&P 500 fell 39.10 (2.09 percent) to 1,833.08. The sell-off came on a day when Chinese trade data disappointed and suggested more weakness in the world's second-biggest economy. But the losses deepened throughout the day, suggesting continued fear over the valuations of high-flying tech companies like Netflix, Facebook and Tesla Motors.These companies were among the biggest losers. Most analysts do not consider conditions comparable to those of the early-2000s tech bubble, but the memory of Nasdaq's plunge in that period is not that distant. "It's certainly a valuation correction," said Jack Ablin, chief investment officer at BMO Private Bank. "We've got lots of liquidity, but we have a stretched market," Ablin said. "Probably the best solution would be to have earnings and revenues rise."