担忧情绪持续发酵，美股三大指数齐跌 道指、纳指跌超1%

Market Overview - The Dow Jones index fell by 1.07% to 46,091.74 points, the S&P 500 index decreased by 0.83% to 6,617.32 points, and the Nasdaq index dropped by 1.21% to 22,432.85 points, reflecting concerns over high valuations and accumulating debt in AI-related stocks [2] - A recent survey indicated that 45% of fund managers view the "AI bubble" as the largest "tail risk" in the current market, with rising concerns over excessive corporate spending, particularly on AI projects [2] Company Performance - Major tech stocks experienced declines, with Nvidia down 2.81%, Amazon down over 4%, and Microsoft down 2.70%. Nvidia has fallen over 10% this month, and both Microsoft and Amazon had their ratings downgraded by Redburn analysts [4][13] - Bitcoin rebounded after dropping below $90,000, raising concerns among tech investors who hold significant amounts of cryptocurrency that the stock market may decline further [3] Company News - Google launched its latest AI model, Gemini 3, emphasizing immediate integration into profitable products, including its search engine [5] - Meta won a federal antitrust case, allowing it to retain ownership of Instagram and WhatsApp without the need to divest these businesses [6][7] - Microsoft, Nvidia, and Anthropic announced a collaboration, with Anthropic investing $30 billion in computing resources on Microsoft Azure, supported by Nvidia [8][9] - Nvidia committed to investing up to $10 billion in Anthropic, while Microsoft will invest up to $5 billion, raising Anthropic's valuation to approximately $350 billion [12] Investment and Development - Geely and Renault plan to invest 3.8 billion Brazilian Reais ($714 million) in Brazil to jointly develop new vehicle models, enhancing competitiveness in South America's largest automotive market [16] - Toyota announced plans to invest $912 million across five U.S. states to boost the production of hybrid vehicle components and vehicles, as part of a broader $10 billion investment commitment over the next five years [17]