下半年第一天，美股“变脸”了，上半年的赢家们大跌

Core Viewpoint - The article discusses a significant shift in market dynamics on the first trading day of the second half of the year, with investors rotating from strong-performing tech stocks to defensive sectors like healthcare [1][5]. Market Performance - On the first trading day of the second half, the Dow Jones Industrial Average rose by 400 points, while the Nasdaq Composite Index fell by 0.82%, indicating a rotation away from tech stocks that had previously led the market [1]. - The AI-related stocks and other tech giants, including Sea Limited, Spotify, and Nvidia, experienced notable declines, with the tech giants index dropping by 1.15% [1][2]. Sector Rotation - The healthcare sector saw a strong rebound, with stocks like Amgen and UnitedHealth Group rising over 4%, and Merck increasing by more than 3% [12][13]. - The consumer discretionary sector also benefited from the rotation, particularly non-essential consumer goods, which had seen significant net selling earlier in the year [13]. Influencing Factors - The market rotation was influenced by several factors, including the start of a new quarter, comments from Federal Reserve Chairman Jerome Powell, and profit-taking ahead of the non-farm payroll data release [5][10]. - Powell's remarks indicated a cautious stance on inflation and suggested that future actions would depend on data, contributing to market volatility [11]. Trading Dynamics - The trading day was characterized as a "violent" unwinding of momentum trades, with a significant sell-off in previously high-performing stocks [10]. - High-profile stocks that had been shorted, such as American Eagle Outfitters and Abercrombie & Fitch, saw price increases, while heavily held stocks like Ralph Lauren performed poorly [14].