黄金盘中创12年来最大单日跌幅，热门中概股普跌，加密货币超17万人爆仓

Group 1: U.S. Stock Market Performance - The U.S. stock market showed mixed results on October 21, with the Dow Jones reaching a historical high, while the S&P 500 closed flat and the Nasdaq experienced a slight decline [1] - Major tech stocks had varied performances, with Amazon rising over 2%, while Google fell more than 2% and Tesla dropped over 1% [1] - General Motors saw a significant increase of nearly 15%, marking its best single-day performance in five years [1] Group 2: Commodity Market Trends - The FTSE A50 futures index fell by 0.25%, closing at 15,193 points [2] - Precious metals experienced substantial declines, with the Philadelphia Gold and Silver Index dropping by 9.57% and spot gold falling over 6% to a low of $4,080.87 per ounce, the largest single-day drop since April 2013 [2] - COMEX gold futures decreased by 5.07%, while COMEX silver futures fell by 6.27% [2] Group 3: Cryptocurrency Market and Investor Sentiment - Multiple cryptocurrencies saw significant declines, with over 170,000 individuals facing liquidation, amounting to over $700 million [3] - Analysts indicated that profit-taking was a primary reason for the market drop, alongside reduced safe-haven demand due to easing global trade tensions [3] - A recent Bank of America survey revealed that 43% of investors view "going long on gold" as the most crowded trade, surpassing the 39% for "going long on the seven major U.S. tech stocks," indicating a strong interest in gold as a safe-haven asset [3]