美股反弹并非信心投票！空头回补造就“虚假繁荣” 上涨行情或难延续

Group 1 - The core point of the articles highlights the significant rebound in the U.S. stock market, driven by aggressive short covering, particularly in the "most-shorted stocks basket," which has surged 16% this month, outperforming the S&P 500's 0.7% increase during the same period [1] - The S&P 500 index has shown remarkable resilience, ignoring various warnings and achieving one of its strongest performance phases since the 1950s, indicating a potential shift in investor sentiment ahead of the Federal Reserve's upcoming interest rate decision [1][2] - There is a growing trend among traders to sell call options to raise funds for purchasing downside protection, reflecting an increase in risk aversion despite the recent market gains [2] Group 2 - Subjective investors have reduced their stock exposure significantly, marking the largest weekly decline since early April, moving from "modestly overweight" to "neutral," which leaves room for potential future buying [3][4] - Quantitative traders have also decreased their stock positions, with trend-following funds reducing their exposure to the lowest level in three months, indicating a cautious approach amidst market volatility [4] - The "unprofitable tech basket," which includes companies like Roku and Peloton, has also risen 16% this month, suggesting a strong performance in speculative sectors, although this may carry higher risks for investors [4][5]