Thoma Bravo co-founder Orlando Bravo said that valuations for artificial intelligence companies are “at a bubble,” comparing it to the dotcom era.

But one key difference in the market now, he said, is that large companies with “healthy balance sheets” are financing AI businesses.

Bravo’s private equity firm boasts more than $181 billion in assets under management as of June, and focuses on buying and selling enterprise tech companies, with a significant chunk of its portfolio invested in cybersecurity.

Bravo told CNBC’s “Squawk on the Street” on Tuesday that investors can’t value a $50 million annual recurring revenue company at $10 billion.

“That company is going to have to produce a billion dollars in free cash flow to double an investor’s money, ultimately,” he said. “Even if the product is right, even if the market’s right, that’s a tall order, managerially.”

OpenAI recently finalized a secondary share sale that would value the ChatGPT-maker at $500 billion. The company is projected to make $13 billion in revenue for 2025.

Nvidia recently said it would invest up to $100 billion in OpenAI, in part, to help the ChatGPT maker lease its chips and build out supercomputing facilities in the coming years.

Other public companies have soared on AI promises, with Palantir’s market cap climbing to $437 billion, putting it among the 20 most valuable publicly traded companies in the U.S., and AppLovin now worth $213 billion.

Even early-stage valuations are massive in AI, with Thinking Machines Lab notching a $12 billion valuation on a $2 billion seed round.

Despite the inflated numbers, Bravo emphasized that there’s a “big difference” between the dotcom collapse and the current landscape of AI.

“Now you have some really big companies and some big balance sheets and healthy balance sheets financing this activity, which is different than what happened roughly 25 years ago,” he said.