美股跌幅扩大，标普500指数跌1%，纳指跌1.85%，道指跌0.3%。

Group 1 - The U.S. stock market experienced a decline, with the S&P 500 index falling by 1% [1] - The Nasdaq composite index dropped by 1.85% [1] - The Dow Jones Industrial Average saw a smaller decrease of 0.3% [1]