U.S. indexes bounced between gains and losses and wound up mixed on Wall Street as trade tensions continued to simmer between Washington and Beijing. The S&P 500 gave up an afternoon gain and closed 0.2% lower Tuesday. The index was weighed down by drops in several tech heavyweights including Nvidia and Broadcom even as most stocks rose. The Dow Jones Industrial Average climbed 0.4%, and the Nasdaq composite dropped 0.8%. China says it's banning dealings by Chinese companies with five subsidiaries of South Korean shipbuilder Hanwha Ocean, swiping at President Donald Trump’s efforts to rebuild the industry in America.