美股创历史新高！分析师警告：泡沫风险显著上升，投资者风险偏好创2001年来最快增长

Group 1 - The US stock market has recently reached historical highs, but several analysts warn that the risk of a bubble is significantly increasing [1][3] - The current market environment shows extreme investor optimism, with risk appetite at a multi-month high, which may indicate an impending correction due to the high level of consensus among investors [1][3] Group 2 - Global central banks' shift towards loose monetary policy has created a conducive environment for stock market bubbles, with US, UK, and European central banks significantly lowering borrowing costs, reducing global policy rates from 4.8% last year to 4.4% [3] - It is expected that this rate will further decline to 3.9% within the next 12 months, providing ample liquidity support for asset price increases [3] - US policymakers are considering regulatory reforms to increase retail investor participation, which may further amplify market volatility, as a larger retail investor base often leads to increased liquidity and volatility, key drivers of bubble formation [3] Group 3 - A recent fund manager survey indicates that investor risk appetite has grown at the fastest pace since 2001 over the past three months, with the largest increase in US stock allocation since December of the previous year [4] - The allocation to technology stocks has seen the largest three-month increase since 2009, reflecting extreme optimism that historically appears near market tops [4] - Fund managers' cash levels have dropped to 3.9%, falling below the critical 4.0% threshold, which is viewed as a clear "sell signal" in trading rules [4] - The proportion of respondents believing that the economy will not enter a recession in the next year has completely reversed, with pessimistic expectations nearly vanishing, indicating a one-sided market consensus that could trigger rapid adjustments with any negative data [4]