US stocks fall as AI valuation fears hit tech and chipmakers

Market Overview - U.S. stocks ended lower, with notable declines in technology companies such as Advanced Micro Devices and Palantir, as investors expressed concerns over high valuations and the sustainability of the AI rally [1][2] - The S&P 500 declined by 0.51% to 6,882.72 points, while the Nasdaq fell by 1.51% to 22,904.58 points, contrasting with a 0.53% rise in the Dow Jones Industrial Average to 49,501.30 points [4] Company Performance - Advanced Micro Devices saw a significant drop of 17% after forecasting disappointing quarterly revenue, indicating challenges in competing with Nvidia [2] - Palantir's shares fell nearly 12%, reversing previous gains attributed to strong quarterly sales [2] - Super Micro Computer's shares surged by 13.8% following an increase in its annual revenue forecast due to sustained demand for AI-optimized servers [5] - Eli Lilly's shares rose about 10% after the company projected 2026 profits exceeding Wall Street expectations [5] Sector Performance - The S&P 500 value index gained for the fifth consecutive session, while the growth index declined, indicating a shift in investor sentiment towards less expensive companies [4] - Seven of the 11 S&P 500 sector indexes rose, with energy leading at a 2.25% increase, followed by a 1.8% gain in materials [4] Employment Data - The ADP national employment report indicated that U.S. private payrolls increased less than expected in January, with job losses in the professional and business services and manufacturing sectors [6]