U.S. stocks closed lower on Tuesday, after President Donald Trump threatened to slap tariffs on up to $400 billion worth of China goods, the latest escalation in a trade dispute that has been unsettling investors for months. The Dow Jones Industrial Average fell 1.2% to 24,669. The blue-chip average, which is closely correlated to trade issues as it is primarily made up of huge multinational stocks, suffered its biggest one-day drop since May 29. That was enough to completely erase its 2018 gains; it is now down 0.1% for the year. Tuesday also represented the Dow's sixth straight daily drop, its longest such streak since March 2017. The S&P 500 fell 0.4% to 2,762. The Nasdaq Composite Index fell 0.3% to 7,726. Among specific stocks, Boeing Co. tumbled 3.8% while Caterpillar Inc. was down 3.6%. 3M Co. shed 2.4%.