美股三大指数开盘涨跌不一，道指跌0.69%，纳指涨0.38%，标普500指数涨0.19%。特斯拉跌超6%，Q2业绩不及预期、下调全年资本支出预测。谷歌涨超4%，创2月以来最高水平，公司Q2业绩超预期、云业务增长强劲。美股航空股走低，美国航空跌超7%，西南航空跌超4%。

Group 1 - The three major U.S. stock indices opened mixed, with the Dow Jones down 0.69%, the Nasdaq up 0.38%, and the S&P 500 up 0.19% [1] - Tesla's stock fell over 6% due to Q2 earnings missing expectations and a downward revision of its full-year capital expenditure forecast [1] - Google's stock rose over 4%, reaching its highest level since February, driven by Q2 earnings exceeding expectations and strong growth in its cloud business [1] Group 2 - U.S. airline stocks declined, with American Airlines dropping over 7% and Southwest Airlines falling over 4% [1]