This paper examines the Buffett Indicator, a valuation metric that compares the total value of U.S. corporate equities to U.S. GDP.
Warren Buffett once referred to the ratio as “probably the best single measure of where valuations stand at any given moment.” Historically, the indicator has averaged approximately 86%, reflecting a long-run relationship between equity market value and economic output.
As highlighted in the paper, that relationship has shifted dramatically in recent years. The indicator crossed 200% in early 2021 and, as of Q3 2025, reached roughly 230%, the highest level observed in more than seventy years of data and 3.2 standard deviations above the historical mean.
The paper explores two competing interpretations. One suggests that structural changes such as globalization, higher corporate profitability, and lower discount rates justify a permanent upward re-rating of equity markets. The other points to decades of historical data showing that extreme deviations from the long-run mean have ultimately reverted over time.
For investors and allocators, the Buffett Indicator provides a useful framework for assessing how equity valuations compare to the size of the underlying economy.