Billionaire Bill Ackman calls Anthropic 'perhaps the greatest business story I've ever seen'

Billionaire investor Bill Ackman said his hedge fund likely won't invest in AI startup Anthropic ( ANTH.PVT ) but that it's still an impressive company.

"Anthropic is perhaps the greatest business story I've ever seen," Ackman said on Wednesday in an interview with Bloomberg TV.

"It's clearly an amazing company," Ackman said, praising the company's revenue and valuation ramp-up along with the quality of its Claude product. He stopped short, however, of saying his hedge fund, Pershing Square ( PS , PSUS ), would add shares of the frontier AI model maker to its portfolio.

"We look to buy businesses that we can predict what they're going to look like over a very long period of time. You know, kind of boring things like perhaps Microsoft or S&P Global or Visa or Mastercard," Ackman said.

"We are less likely to be an investor in a very fast-growing business that's consuming a huge amount of capital, and you're betting on kind of the lines crossing at some point in the future."

Ackman also questioned how durable the advantage of the frontier models is against lower-cost alternatives.

"Query whether the frontier model companies will be able to maintain their market presence in light of the power of … open source and open weight models," he added.

The point underscores a wrinkle investors are now grappling with ahead of the planned IPO Anthropic is targeting later this year.

Anthropic hasn't publicly shared its customary IPO paperwork yet, but earlier this week, a Reuters report revealed a leaked copy of the filing. That report showed Anthropic's 2025 revenue grew 12 times, ending the year at nearly $4.6 billion. Its net losses also mounted, soaring to $42 billion in 2025.

Still, the company is targeting a $2 trillion valuation in its public debut. Successful public debuts for Anthropic and, eventually, rival OpenAI ( OPAI.PVT ) hang on whether investors will have enough optimism that revenue will eventually outpace spending. Two analysts have already questioned the math .

Ackman's comments don't mean his hedge fund is steering away from the AI boom, though. He said Pershing currently holds shares of Meta ( META ), Amazon ( AMZN ), and Microsoft ( MSFT ), according to an August filing.

David Hollerith covers a range of developments throughout the financial sector, from Wall Street to banking and asset management to crypto and fintech. Email him at david.hollerith@yahoofinance.com. Follow him on X at @DsHollers.