CAPE at 42.15 and Buffett Ratio 238: Bubble Warning Echoes 1999

For allocators, the uncomfortable math is simple. The S&P 500's Shiller CAPE sits at 42.15, the second-highest level in more than a century, only two points below the November 1999 top. With the Buffett indicator at 238—well above Warren Buffett's 200 overvaluation line—the parallel to the era that produced a 49% S&P 500 drawdown by October 2002 deserves more than a passing look.

Former Federal Reserve Bank of New York president Bill Dudley has put a valuation question back at the center of the investing debate in late August 2026. In a Bloomberg column cited by The Motley Fool, Dudley argues that the U.S. stock market is in bubble territory, and the numbers behind his claim are hard to dismiss. The Warren Buffett indicator—total U.S. market capitalization divided by gross domestic product—now sits at about 238, well above the 200 threshold that Warren Buffett has called a sign of strong overvaluation. The Shiller CAPE ratio, which compares S&P 500 prices to ten years of inflation-adjusted earnings, stands at 42.15, the second-highest reading in more than a century and just below the 44.19 peak it reached in November 1999. These are not marginal overruns; they are levels that have historically preceded long and painful contractions in equity prices.

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When it finally burst in early 2000, the consequences were severe: by October 2002 the Nasdaq Composite had lost 78% of its value and the S&P 500 had lost 49%.

The historical parallel is both powerful and cautionary. The article opens with Alan Greenspan's December 1996 speech, when the then-Federal Reserve chairman asked how one could know whether 'irrational exuberance has unduly escalated asset values.' The warning triggered a short global sell-off, but the dot-com bubble kept inflating for roughly three more years. When it finally burst in early 2000, the consequences were severe: by October 2002 the Nasdaq Composite had lost 78% of its value and the S&P 500 had lost 49%. Greenspan was right about the manic pricing, but enormously early in calling it. Investors who sold in 1996 missed three more extraordinary years of gains, while those who stayed too long suffered a deep drawdown.

That timing problem remains relevant today. The fact that the CAPE ratio is at 42.15—only about two points below its November 1999 extreme—does not mean a top is imminent. Valuation metrics are not short-term timing tools, and bubbles can persist long after they become obvious. Dudley's warning, like Greenspan's before it, may set off a brief pullback without ending the advance. But the current numbers do have a bearing on long-run expected returns. At CAPE levels above 40, the historical record points to subdued real returns over the following decade. That is the financial reality behind the question of what Greenspan would say: he would probably agree with Dudley that the market is overvalued, while knowing that 'overvalued' can coexist with further gains.