美股三大指数集体收跌！科技巨头独木难支，特朗普签署新关税行政令，全球贸易紧张局势升级

Market Overview - The US stock market closed lower on July 31, with all three major indices declining despite strong performances from Microsoft and Meta [1][2] - The Dow Jones Industrial Average fell by 0.74% to 44,130.98 points, the S&P 500 decreased by 0.37% to 6,339.39 points, and the Nasdaq Composite slightly dropped by 0.03% to 21,122.45 points [2][3] - Both the S&P 500 and Nasdaq reached historical highs during the trading session but retreated, indicating cautious investor sentiment [2] Company Performance - Microsoft and Meta reported quarterly earnings that exceeded expectations, with Microsoft shares rising approximately 3.95% and Meta's shares increasing by 11.25% [4][5] - Microsoft's cloud service Azure achieved annual revenue exceeding $75 billion, while Meta provided an optimistic revenue forecast for Q3, surpassing Wall Street expectations [4] - Other major tech stocks showed mixed results, with Apple down 0.71%, Nvidia down 0.78%, and Google down 2.36%, while Amazon rose by 1.70% and Tesla fell by 3.38% [4][5] Chinese Stocks - The Nasdaq Golden Dragon China Index rose by 0.66%, with notable performances from Alibaba (up 2.77%) and NIO (up 7.98%), while JD.com fell by 0.82% [5][6] Earnings Reports - Apple reported Q3 revenue of $94.04 billion, a year-over-year increase of 9.6%, and a net profit of $23.43 billion, also up by 9% [8] - Amazon's Q2 revenue reached $167.7 billion, a 13% increase year-over-year, with a net profit of $18.16 billion, up 34.7% [8] Trade Policy Impact - President Trump's new tariff measures, including a 90-day extension of tariffs on Mexico and an increase in tariffs on Canada from 25% to 35%, have raised concerns about global trade tensions [9]