Anthropic raises $65B at ~$965B valuation, eclipsing OpenAI, and confidentially files for IPO

Anthropic closed a $65 billion Series H round at a $965 billion post-money valuation, the company and reporting said on May 28, 2026, surpassing OpenAI to become the most valuable AI startup for the first time. The round was co-led by Altimeter Capital, Dragoneer, Greenoaks, Sequoia Capital, Capital Group, Coatue and D1 Capital Partners, with additional participation from Baillie Gifford, Blackstone, Brookfield, D.E. Shaw Ventures, DST Global, Fidelity, Samsung, SK Hynix and Micron; roughly $15 billion came from hyperscalers, including $5 billion from Amazon announced in April.

Anthropic said proceeds would 'advance our safety and interpretability research, expand compute to meet growing demand for Claude, and scale the products and partnerships our customers rely on.' For comparison, OpenAI raised $122 billion at an $852 billion post-money valuation in March 2026. On June 1, Fortune (citing Bloomberg) reported Anthropic had submitted confidential draft paperwork to the SEC for a proposed IPO that could launch as early as fall 2026, with share count and price not yet set, and with Goldman Sachs, JPMorgan Chase and Morgan Stanley among banks considered for lead roles. On financials, Anthropic said run-rate revenue had crossed roughly $47 billion in mid-May; Fortune reported the company expects about $10.9 billion in Q2 revenue—more than double the prior quarter—and annualized run-rate revenue exceeding $50 billion by month-end, projecting a path toward its first operating profit.

The raise and filing position Anthropic to potentially reach public markets ahead of OpenAI, which was reportedly preparing its own confidential filing for fall 2026.