The Stock Market Has Not Been This Expensive Since the Dot-com Bubble's Peak. History Says to Prepare for What Might Come Next.

The S&P 500's Shiller CAPE ratio has reached its highest level since the dot-com bubble peak, driven by unsustainable AI-related earnings gains and massive capital expenditures. While super-intelligent AI could justify current valuations, the market faces significant downside risk. Investors should maintain diversified portfolios rather than betting heavily on either scenario.