Legendary global macro trader Paul Tudor Jones is warning that asset prices are too high. And furthermore, he’s concerned about what the next recession might look like. He shared his thoughts on Monday during a conversation with Goldman Sachs CEO Lloyd Blankfein as part of the firm’s “Talks at GS” series.

The hedge fund billionaire, who rarely gives interviews or makes public comments on the markets, cautioned that across asset classes “you have to be thinking this is a highly dubious sustainable price.”

Jones doesn’t think the low interest rates we have now due to easy monetary policy are sustainable over time. He said that interest rate policy is “crazy.” He further argued that the Trump administration’s stimulative fiscal policy isn’t sustainable either.

“You look at prices of stocks, real estate, anything,” he said. “We’re going to have to mean revert to a normal real rate of interest with a normal term premium that’s existed for 250 years. We’re going to have to get back to that. We’re going to have to get back to a sustainable fiscal policy and that probably means the price of assets goes down in the very long run.”

In the short run, the market is “jacked up and ready to go,” he said. Blankfein added that it’s like “pouring lighter fluid on an already lit fire.”

“We don’t have any stabilizers”

During the financial crisis, central banks had a lot of room to ease monetary policy and governments had more flexibility to push stimulative fiscal policy. Today, there’s less room and flexibility.

“The next recession is really frightening because we don’t have any stabilizers,” Jones said. “We’ll have monetary policy, which will exhaust really quickly, but we don’t have any fiscal stabilizers.”

Jones, 63, began his career as a commodities trader in the cotton pits in the 1970s before transitioning to macro trading and founding his hedge fund, Tudor Investment Corp. He shot to notoriety after predicting the market crash of October 19, 1987, known as “Black Monday” when the Dow Jones dropped more than 22%.

“The one thing I’ve learned over the past 40 years — these price patterns it’s the same old story so often just with different characters, different times, different plots,” Jones said.

A year after his 1987 bet, he founded Robin Hood, a nonprofit dedicated to combating poverty in the New York City area. Over the last 30 years, Robin Hood has given away more than $3 billion.

In recent years, Jones’s philanthropic efforts have translated to the private sector. In 2013, with the help of Deepak Chopra, Rinaldo Brutoco, Arianna Huffington, Paul Scialla, and more, Jones co-founded JUST Capital, a nonprofit with a mission of promoting economic justice by engaging the public’s input. After surveying thousands of Americans on what this means, JUST has been compiling a list of the 100 “most just” companies.