滚动更新丨美股三大指数小幅高开，热门中概股涨跌互现

Group 1 - The three major U.S. stock indices opened slightly higher, with the Dow Jones up 0.06%, Nasdaq up 0.15%, and S&P 500 up 0.04% [1] - Snowflake's stock surged over 11% after the company reported Q2 earnings that exceeded market expectations [1] - Nvidia's stock rose over 1% during the trading session [1] Group 2 - Chinese concept stocks showed mixed performance, with Alibaba and JD.com down over 2%, while NIO and Li Auto rose over 2% [1] - U.S. stock index futures were slightly higher, with Dow futures up 0.13%, S&P 500 futures up 0.05%, and Nasdaq futures up 0.03% [2] - Nvidia's stock turned positive in pre-market trading after previously declining by 3.3% [2]