Warren Buffett: One metric tells me the most about the future

Warren Buffett made a name for himself and became a multi-billionaire by making some savvy moves in the stock market. So, it might surprise some folks to hear him say that for stock market investors, the most important metric to watch is found in the bond market.

“Everything in valuation gets back to interest rates,” Buffett said to Yahoo Finance’s Andy Serwer in April.

Recently, Buffett has been fielding a lot of questions about stock market valuations and how one should value individual businesses. And repeatedly, Buffett responded by pointing to interest rates.

It’s not as simple as CAPE or market cap to GDP

At Berkshire Hathaway’s recent annual shareholders meeting, an investor asked Buffett about the relevance of two popular measures of stock market value: 1) market cap-to-GDP, which Buffett once heralded as “probably the best single measure of where valuations stand at any given moment” and 2) the cyclically-adjusted price-earnings ratio (CAPE), which was made famous by Nobel prize winner Robert Shiller and was seen as accurately predicting the dot-com bubble and the housing bubble.

“Every number has some degree of meaning,” Buffett said. “It means more sometimes than others. … And both of the things that you mentioned get bandied around a lot. It’s not that they’re unimportant. … They can be very important. Sometimes they can be almost totally unimportant. It’s just not quite as simple as having one or two formulas and then saying the market is undervalued or overvalued.”

Having said that, Buffett does see a metric that is arguably more significant than these two heralded measures of stock market value.

“The most important thing is future interest rates,” Buffett said. “And people frequently plug in the current interest rate saying that’s the best they can do. After all, it does reflect the market’s judgment. And the 30-year bond should tell you what people are willing to put out money for 30 years and have no risk of dollar gain or dollar loss at the end of the 30-year period. But what better figure can you come up with? I’m not sure I can come up with a better figure. But that doesn’t mean I want to use the current figure, either.”

Warren Buffett
Warren Buffett

So, what does this all mean in the context of today’s historically low interest rate environment? In an interview with CNBC’s Becky Quick, Buffett said that if these rates were guaranteed to stay low for 10, 15 or 20 years, then “the stock market is dirt cheap now.”

Berkshire’s long-term returns depend on interest rates

Early during Berkshire’s annual meeting, Buffett fielded a question about calculating the intrinsic value and forecasting 10-year forward returns for Berkshire Hathaway (BRK-A, BRK-B).