美股三大指数涨跌不一，军工股全线走强，中概股多数上涨阿里涨超5%

Market Overview - The U.S. stock market showed mixed results with the Dow Jones increasing by 270.03 points (0.55%) to close at 49,266.11, while the Nasdaq fell by 104.26 points (0.44%) to 23,480.02, and the S&P 500 rose slightly by 0.52 points (0.01%) to 6,921.45 [1] - Analysts noted a degree of profit-taking after several days of gains, with geopolitical risks remaining high as the market prepares for the upcoming earnings season [1] Economic Data - Initial jobless claims in the U.S. rose slightly, indicating continued weakness in labor demand, corroborating previous ADP employment data and JOLTS job openings data [1] - The market is awaiting the December non-farm payroll report, which is expected to be a significant macroeconomic data point following the end of the longest government shutdown in U.S. history [1] - Fitch Ratings upgraded its U.S. economic growth forecast, predicting a GDP growth of 2.1% in 2025 and 2.0% in 2026, accounting for delayed data due to the government shutdown [1] Sector Performance - Large-cap tech stocks mostly declined, with Nvidia down 2.15%, Microsoft down 1.11%, and Apple down 0.5%, while Tesla rose 1.02% and Amazon increased by 1.96% [2] - The defense sector saw gains, with Northrop Grumman up 2.4%, Lockheed Martin up 4.3%, and General Dynamics up 1.7%, following Trump's proposal to increase military spending to $1.5 trillion for FY2027, a more than 50% increase from the current record budget of $901 billion [2] Company News - Mining giants Glencore and Rio Tinto have restarted merger talks, with discussions focusing on a potential all-stock merger that could involve parts or all of their businesses [5][6] - General Motors announced a $6 billion one-time charge related to scaling back its electric vehicle investments, primarily due to changes in government policy and a cooling demand for electric vehicles [8] - Google is enhancing its Gmail service with new Gemini features, including AI-generated email summaries and real-time proofreading tools, aimed at improving user experience [7]