The Nasdaq Composite Index on Friday briefly gave up all of its gains for 2018 in late afternoon trade, marking a reversal of fortune for the index that has represented risk appetite on Wall Street throughout the market’s brisk rally to records. The Nasdaq [c: COMP] was off 2.5% at 6,904. The Nasdaq was briefly in negative territory for 2018, but was recently clinging to a slight 0.1% year-to-date rise. The index also dropped in negative territory for the year on Monday but recovered those losses over the past three sessions as worries about trade conflicts between China and the U.S. and a technology-driven selloff cooled. However, a proposal by President Donald Trump to impose stiffer tariffs on Beijing has introduced fresh volatility in to the market. The Dow Jones Industrial Average DJIA, -2.34% was off nearly 700 points at its lows, or 2.8% and the S&P 500 index SPX, -2.19% sank 2.3% at 2,599.