The Dow fell more than 400 points Tuesday morning, turning negative for the year, as US Treasury yields surged to their highest levels in over a decade. The Dow fell 427 points, or 1.3%. The benchmark S&P 500 declined 1.5% and the Nasdaq Composite lost 1.8%, extending the late summer selloff in stocks. Stocks have marched higher for most of this year, as artificial intelligence excitement took hold on Wall Street and powered tech stocks to stratospheric heights. But that rally petered out in August, as strong economic data had investors worried that a resilient economy and piping hot labor...