What the Buffett Indicator Says: This Is One of the Priciest Markets in 100 Years

TL;DR By the Buffett Indicator (market cap / GDP), the U.S. market is about 140–142% above its long-run average. Every past stretch this rich — 1929 (+208%), 2000, 1966 — was followed by a dismal decade. This isn't a crash prophecy; it's a case for lowering your forward return expectations.

Straight to It: This Is Among the Priciest Markets in a Century

The one tool Buffett called "probably the single most reliable metric at any given moment" is now flashing an extreme. It's the Buffett Indicator.

The mechanics are beautifully simple. You take the combined market cap of every publicly traded U.S. company and compare it to GDP — the size of the entire U.S. economy that year. The question is one line: has the stock market's price grown bigger than the economy meant to support it? If the economy doubles, it's logical that the companies inside it should roughly double too.

When the ratio is about 1-to-1 — market value near GDP — that's roughly normal. The zone where Buffett gets excited to buy, where stocks are actually cheap, sits around 70–80% of GDP. And today? The market is priced at more than twice the size of the economy.

My Version of the Indicator Reads 140–142% Overvalued

The version I watch is based on the S&P 500. Because the S&P 500 is a market-cap index, a 10% rise means market cap rose 10% — which makes it clean to lay against GDP.

The S&P is around 7,500 today, and when I take that index over GDP and compare it to the average of 100 years of data, we're sitting about 142% above that average. Why that number is frightening only becomes clear when you set it next to history.

Line It Up Against History and the Picture Sharpens

The bottom line: today's overvaluation is worse than the peak of the dot-com bubble.

On my S&P-based indicator, the 2000 peak was about 47% overvalued. The next 10 years returned roughly -2.6% a year excluding dividends — negative even with dividends. For context, after 2000 it took the S&P 12 years to make a new high and the Nasdaq 16 years; the Nasdaq fell more than 80% from its 2000 peak to its 2002–2003 bottom.

Go further back to September 1929 and you find a staggering 208% overvaluation, followed by -9.5% a year for a decade. Flip it: 1982 was 67% undervalued — the equivalent of the S&P sitting at 1,000 today. With the index in the 7,200s, that was a different world. And 1966–67, when Buffett wound down his partnership saying there was nothing to buy, was about 23% overvalued.

Period	vs. fair value	Next 10-yr annual return
Sept 1929	+208%	-9.5%
2000 peak	+47%	-2.6%
1966–67	+23%	Poor
1982	-67% (undervalued)	Strong
Today	+140–142%	?

The Rule: The Richer the Start, the Worse the Next Decade

Zoom out from single cases to 100 years and 401 quarters, and a pattern appears.

In the 134 times the market was undervalued by 30% or more, the following 10 years averaged 10.7% a year excluding dividends — closer to 13–14% with dividends historically. But as you move into overvaluation, that number steps down: 10.7 → 9 → 2.1 → -1.2 → -2 → -2.4. That final -2.4% is the average for stretches 50%+ overvalued. Right now we're at 141%.

Valuation band	Next 10-yr annual return (ex-dividends)
30%+ undervalued	10.7%
Near fair value	9%
Mildly overvalued	2.1%
Moderately overvalued	-1.2% to -2%
50%+ overvalued	-2.4%

The Counterargument for Higher Valuations — I Accept Part of It

To be fair, there's a real case for why today's valuations can sit higher than the past, and I buy a good chunk of it.

A century ago — even 60 years ago — making money meant hiring lots of people and building factories. It was intensely capital-intensive. That's no longer true. Companies can earn far higher returns on capital now, so richer valuations are reasonable. But at the end of the day, a dollar of profit is still a dollar of profit. Past a certain point, you have to stop overpaying.

So the Conclusion Isn't a Crash Prophecy

I'm not saying a crash comes tomorrow. High readings can stay high for a long time, and we've been overvalued for years now.

But the indicator tells you one clear thing: buying today means paying one of the highest prices in history for a dollar of American business. Prepare for the odds that the next 10–15 years won't be a great market — and know you can still profit handsomely if you stay disciplined. Berkshire's record cash pile is that discipline made real. Why the market keeps climbing despite this valuation is where I pick up in why the market keeps hitting highs on bad news.