A股泡沫到底大不大？美联储一开口美股就慌，散户警惕两个信号！

Group 1 - The core concern is the potential asset price bubble in the US, which has raised alarms among domestic investors regarding the A-share market's valuation and growth [1][2] - The Shanghai Composite Index and CSI 300 Index have seen a cumulative increase of approximately 15% from early 2025 to September 25, while the STAR Market and ChiNext Index have surged by 45% and 75% respectively since the initiation of the US-China tariff dispute on April 8 [2][5] - The valuation metrics indicate that the Shanghai Composite Index is at the 95.84th percentile of its ten-year valuation range, suggesting a significant valuation bubble, while the CSI 300 Index is at the 85th percentile, indicating it is also relatively expensive [5][6] Group 2 - The ChiNext Index, despite its substantial price increase, shows a relatively moderate valuation at the 52.4th percentile, indicating less bubble risk compared to traditional sectors represented by the Shanghai Composite Index [6][8] - The disparity in performance between the indices is attributed to the underlying asset quality, with traditional sectors experiencing weak earnings growth, while high-tech sectors are witnessing both earnings and valuation growth [8][12] - The ten-year valuation period is deemed more relevant for A-shares due to the market's internationalization since the establishment of the Shanghai and Shenzhen Stock Connects, which has altered the valuation landscape significantly [9][11]