Tech stocks sink as Chinese competitor threatens to topple their AI domination 

New York — Wall Street is tumbling Monday on fears the big U.S. companies that have feasted on the artificial-intelligence frenzy are under threat from a competitor in China that can do similar things for much cheaper. The S&P 500 was down 1.9% in early trading. Big Tech stocks that have been the market’s biggest stars took the heaviest losses, with Nvidia down 11.5%, and they dragged the Nasdaq composite down 3.2%. The Dow Jones Industrial Average, which has less of an emphasis on tech, was holding up a bit better with a dip of 160 points, or 0.4%, as ofmore