美股全线转跌，中概股下挫，蔚来跌超8%，贵金属再跳水，巴菲特正式退休

Market Overview - The U.S. stock market opened slightly higher but turned to decline, with the Dow Jones down by 117.32 points (-0.24%), Nasdaq down by 40.22 points (-0.17%), and S&P 500 down by 12.48 points (-0.18%) [2] - Major tech stocks showed poor performance, with most of the "Big Seven" tech companies in the U.S. experiencing declines [2] Tech Stocks Performance - Nvidia opened high but saw its gains diminish, while other tech giants like Tesla, Google, Apple, Microsoft, Amazon, and Meta Platforms also recorded slight declines [3] - The Nasdaq Golden Dragon China Index saw a decline of over 1%, with notable drops in companies like Li Auto (-8.2%), Xpeng (-5.9%), and NIO (-4.9%) [3] Precious Metals and Commodities - Precious metals experienced a significant drop, with platinum down by 7.87% and silver down by 6.46% as of the latest reports [4][5] - Gold prices showed a slight increase of 0.03%, while crude oil futures saw a minor rise [4] Wealth Increase Among Billionaires - The wealth of the world's top 500 billionaires surged by a record $2.2 trillion in 2025, with a significant portion attributed to just eight individuals, including Elon Musk and Jeff Bezos [6] Federal Reserve's Monetary Policy - The Federal Reserve's recent meeting minutes indicated a lack of consensus on interest rate cuts, suggesting potential future easing that could benefit the stock market [8] - Analysts predict that the Fed may have room for further rate cuts, which could positively impact small and mid-cap companies [8]