Michael Burry, the famed investor behind “The Big Short,” is betting artificial intelligence is more of a bubble than a revolution.

Burry’s fund, Scion Asset Management, disclosed on Monday that it bought puts — bets that share prices will fall — on two stars of the AI wave: Nvidia (NVDA) and Palantir (PLTR). Scion bought roughly $187.6 million in puts on Nvidia and $912 million in puts on Palantir, according to Securities and Exchange Commission filings.

Burry is known for his prophetic call that the US housing market would collapse in 2008. He was profiled in the 2010 book “The Big Short: Inside the Doomsday Machine,” by Michael Lewis, and portrayed by Christian Bale in the 2015 film adaptation.

Now Burry is betting against the hottest AI stocks on the market at a time when concerns are mounting about a bubble. Tech and AI stocks have carried the market in recent months. The S&P 500, which is increasingly concentrated in tech companies, is trading at historically expensive levels.

Meanwhile, the circular financing of AI deals has raised eyebrows on Wall Street, with many tech companies entwined in a massive web of deals with each other. Some investors are also skeptical whether future profit growth will continue to justify the enormous amounts of spending taking place.

The tech-heavy Nasdaq Composite tumbled 2.04% on Tuesday, posting its worst day since August. Meanwhile, the S&P 500 fell 1.17%.

Burry made a splash among investors on Thursday, when he posted on X for the first time since 2023. In his post, he shared a photo of Bale portraying him in “The Big Short” and wrote: “Sometimes, we see bubbles. Sometimes, there is something to do about it. Sometimes, the only winning move is not to play.”

Four days later, Burry’s fund disclosed its bearish positions in Nvidia and Palantir. The SEC filings are for the third quarter of this year. Scion Asset Management did not respond to a request for comment.

Angelo Zino, a tech analyst at CFRA Research, said a pullback in tech stocks was overdue, given how far they have rallied in recent months. He said Burry’s comments likely exacerbated concerns.

Burry has made public calls about the market in the years since “The Big Short.” He has not always been correct. The hedge fund manager in January 2023 infamously posted on X, “Sell,” before posting two months later, “I was wrong to say sell.”

Nonetheless, his words carry weight on Wall Street.

Burry’s return to social media comes at a time when investors have voiced concerns about expensive valuations, a market concentrated on a handful of large companies and rising investor expectations.

For example, Palantir beat Wall Street forecasts in earnings reported Monday. Yet it wasn’t enough to impress traders after a series of strong earnings results.

On Tuesday, its shares tumbled 7.95% — their worst day since August.

Palantir was the top performing stock in the S&P 500 in 2024 and is in the top five performing stocks this year. Its shares are still up 152% this year.

The company’s earnings results on Monday were “stellar,” according to CFRA Research’s Zino, but the company’s valuation — a measure of how pricey it is — “is a bit extreme.”

“Despite the great results, when you coincide that with the comments that Michael Burry made and everybody already talking about concerns about an AI bubble, I think the combination of those factors really helped drive a pullback in the shares, the broader tech index and as a result the broader markets,” Zino said. “We’re not overly concerned about the pullback, but I would say it’s one of those situations where you’ve got to keep an eye on it.”

Meanwhile, Nvidia shares fell 3.96% on Tuesday. Shares are still up 48% this year.

Alex Karp, CEO at Palantir, told CNBC on Tuesday that people betting against the company — including Burry — are “crazy.”

“When I hear short sellers attacking what I believe is clearly the most important software company in America, therefore in the world, in terms of our impact, … it just is super triggering,” Karp said.

“It’s crazy motivating,” Karp said. “Every time they short us, we are just like tripling down on getting the better numbers, in part honestly, to make them poorer.”