Anthropic files confidential S-1 at ~$965B valuation, leapfrogging OpenAI in IPO race

Anthropic's confidential draft S-1, filed June 1, formally launches an IPO process at a roughly $965 billion post-money valuation, on the back of a $65 billion Series H round. The company reports a $47 billion annualized revenue run rate as of May 2026 — a near-5x jump year over year — which it positions as proof of enterprise pull-through from Claude's coding and agentic capabilities.

The filing puts Anthropic ahead of OpenAI in the public-markets race, an ordering few would have predicted a year ago. CNBC's Tech Download casts the listing as the first big stress test of AI-boom valuations: enterprises are simultaneously ramping AI spend and looking to rein in costs, and a public Anthropic will have to defend gross margins that are heavily exposed to inference economics and compute contracts.

The market reaction in the analyst community was mixed. Investors like Jamin Ball treated the $965B mark as validation of enterprise adoption, while others joked it 'reads like any startup fundraise' and questioned sustainability. The timing — a freeze-the-frontier safety plea in the same week as a near-trillion-dollar IPO — gave critics on r/artificial ('anthropic wants a global ai freeze, they're also about to ipo at $1 trillion,' 122 upvotes) an easy contradiction to seize on.

What to watch: the eventual public S-1 numbers (the confidential draft hides the details), the lockup and governance structure given Anthropic's public-benefit-corporation framing, and whether a successful debut pulls OpenAI's own listing timeline forward. The broader signal is sector maturation: AI's leading labs are now graduating from private megarounds to the discipline of quarterly earnings.