Anthropic overtakes OpenAI at $965B valuation, files confidentially for IPO

Anthropic confirmed on June 1 that it has confidentially submitted a draft S-1 registration statement to the SEC under Section 135 of the Securities Act, opening the door to an initial public offering pending completion of regulatory review. The filing landed on the back of its Series H round, which the company says values it at $965 billion — eclipsing OpenAI to make Anthropic the most valuable AI startup in the world. The round was led by Altimeter, Dragoneer, Greenoaks and Sequoia, with Amazon committing up to $25 billion as part of a broader hyperscaler tranche.

The mechanics are striking: reporting puts Anthropic's annualized revenue jump from roughly $9 billion to north of $30 billion, a surge attributed largely to Claude Code adoption inside enterprises. The IPO race with OpenAI now reads as the defining exit narrative for the labs that have crossed the $60B-plus valuation threshold, and the confidential route lets Anthropic test investor appetite without prematurely disclosing financials.

Competitively, the move tightens Amazon's bet on Anthropic just as the rivalry with OpenAI intensifies on multiple fronts — cybersecurity (Claude Mythos vs GPT-5.5 Cyber), enterprise governance, and now public-market validation. Anthropic's official account framed the filing plainly: 'Pending completion of SEC review, this gives us the option to pursue an initial public offering.'

Skeptics in the developer community questioned the durability of a near-trillion-dollar private valuation, especially following a chilly reception to Opus 4.7 and the rapid 41-day upgrade cadence to Opus 4.8. Watch for whether the confidential filing converts into an actual public roadshow, and how the SEC treats a loss-making frontier lab at this scale.