The US stock market CAPE ratio climbs to 42, valuation approaching dot-com bubble levels, future decade returns likely under pressure.

As of August 7, the S&P 500’s Shiller Price-to-Earnings Ratio (CAPE) rose to 42.39 times, far exceeding its long-term average of 17.40 times. It is only lower than the historical peak of 44.19 times during the dot-com bubble and surpasses the 32.56 times valuation level before the 1929 Great Crash. Currently, the CAPE has entered the extreme range where it exceeds 40 times for only the second time in history. Analysts note that the CAPE metric is primarily used to measure long-term investment return expectations, not to predict short-term market tops. Almost all historical cases where the CAPE exceeded 40 times were concentrated in the 1999-2000 dot-com bubble period, so one cannot simply infer that U.S. stocks will inevitably enter a "lost decade" in the next ten years based on a single bubble cycle. However, high valuations mean the long-term valuation buffer of U.S. stocks is shrinking. Future market returns will depend more on corporate earnings consistently exceeding expectations, rather than further valuation expansion. Market participants believe that productivity gains, margin improvements and corporate earnings growth brought by the artificial intelligence (AI) wave could help sustain high valuations for a longer period. But if AI earnings fall short of expectations or real interest rates continue to rise, the high valuation environment could amplify market correction pressures. The core signal from the CAPE is that U.S. stocks’ expected returns over the next decade may face downward pressure, but this metric does not directly mean U.S. stocks are about to peak, nor can it infer that actual returns over the next ten years will definitely be negative. (Jinshi)