美国股市跌幅扩大，纳斯达克指数下跌3.00%。

Core Points - The U.S. stock market has experienced a significant decline, with the Nasdaq index dropping by 3.00% [1] Group 1 - The overall market downturn indicates a bearish sentiment among investors [1] - The Nasdaq index's decline reflects broader trends affecting technology and growth stocks [1] - The extent of the drop suggests potential volatility in the market moving forward [1]