The Dow Jones industrials are down 291 points, or 1.2 percent, to 24,697, after dropping more than 400 points in morning trading. The S&P 500 is lower by 16 points, or 0.6 percent, at 2,756, and the Nasdaq composite is down 61 points, or 0.8 percent, to 7,685. U.S. stock markets are opening sharply lower Tuesday as tensions over trade between the U.S. and China seem closer to a boil. U.S. stock markets are set for a sharply lower open as tensions over trade between the U.S. and China seem closer to a boil.