The Financial Times reports that some of OpenAI’s own investors are casting doubt on the AI firm’s $852 billion valuation, as OpenAI rushes to reframe its business around enterprise clients and hold off rising competition from rival developer Anthropic.

Anthropic has posted explosive revenue growth in recent months: its annualized revenue surged from $9 billion at the end of 2025 to $30 billion by the end of March, with the jump driven almost entirely by booming demand for its AI-powered coding tools. One investor that backs both companies told the FT that justifying OpenAI’s current funding round requires projecting the company will hit an IPO valuation of $1.2 trillion or higher. That lofty requirement makes Anthropic’s current $380 billion valuation read as a far more attractive relative deal.

Trading activity on private secondary markets tells a similar story right now: demand for Anthropic shares has grown nearly unquenchable, while OpenAI shares currently trade at a discount to the company’s latest private valuation.

This kind of high-stakes valuation debate is not new for OpenAI CEO Sam Altman. During his tenure leading top startup accelerator Y Combinator, he witnessed first-hand the outcomes of aggressive valuation inflation: some portfolio companies were left financially stranded when market expectations didn’t pan out, while others grew to far outperform even their earliest lofty price tags.

OpenAI CFO Sarah Friar pushed back against the criticism, telling the FT that the company’s $122 billion capital raise — the largest private fundraising round in history — serves as clear evidence of sustained investor confidence in OpenAI. Not all industry observers are convinced, however. Jai Das, president of investment firm Sapphire Ventures, who holds no stake in either OpenAI or Anthropic, told the FT he sees OpenAI as “the Netscape of AI.” The reference points to the once-dominant early web browser that was eventually outcompeted by Microsoft before being acquired and absorbed by AOL.

Update: This piece has been revised to remove an investor quote that was originally published by the Financial Times, and later retracted by the outlet.