S&P 500
Valuation Alarm Bells Ring on Wall Street: Shiller CAPE Hits 39.8 as AI Enthusiasm Hits a Wall
The S&P 500 index reached a sobering milestone on March 9, 2026, as the widely followed Shiller CAPE (Cyclically Adjusted Price-to-Earnings) ratio climbed to 39.8. This level marks the highest valuation for the U.S. stock market since the peak of the dot-com bubble