Anthropic quietly files for the biggest AI IPO in history
Anthropic confidentially filed a draft S-1 with the SEC on June 1, 2026. The filing starts the formal clock on what analysts at Bloomberg and Fortune describe as a likely trillion-dollar public debut, potentially this fall.
The numbers behind the filing are wild even by 2026 standards. Anthropic’s revenue run-rate hit approximately $47 billion in May 2026, up from $9 billion at the end of 2025. That is a 5x annual growth rate. The company told investors it expects to more than double revenue to $10.9 billion in Q2 and deliver its first operating profit, according to the Wall Street Journal. The caveat: it may not stay profitable through the year because of compute costs.
Those compute costs are the story within the story. Anthropic agreed to pay SpaceX $1.25 billion per month through 2029 to rent the entire Colossus 1 data center near Memphis, Tennessee. That is $15 billion per year to a single vendor. Colossus 1 runs over 220,000 NVIDIA GPUs across H100, H200, and GB200 accelerators, drawing more than 300 megawatts of power. For comparison, Google just signed its own deal with SpaceX at $920 million per month for roughly half that compute capacity.
The $1.25B monthly SpaceX bill will dominate every margin discussion when the public S-1 drops.
Anthropic’s last private fundraise closed days before the filing. The Series H brought in $65 billion at a $965 billion post-money valuation, co-led by Altimeter Capital, Dragoneer, Greenoaks, Sequoia Capital, Capital Group, Coatue, and D1 Capital Partners. Samsung, SK Hynix, and Micron joined as strategic infrastructure partners. Fifteen billion of the round came from previously committed hyperscaler investments, including $5 billion from Amazon.
Morgan Stanley and Goldman Sachs will lead the IPO. Daniela Amodei, Anthropic’s president, confirmed the confidential filing at the Bloomberg Tech conference in San Francisco, calling it an option to go public after SEC review. She also said the high cost of developing AI models is what drives companies to the public markets in the first place. Not exactly a reassuring pitch for long-term margin optimists.
The competitive timing matters. OpenAI raised $122 billion at an $852 billion valuation in March 2026 but has not yet filed its own S-1. Anthropic is now valued higher than OpenAI despite lower revenue, which means public market investors will be pricing in Anthropic’s enterprise momentum, particularly Claude Code and the Glasswing cybersecurity program, rather than consumer reach. SpaceX is also in the middle of its own $75 billion IPO roadshow, pricing June 11 and trading June 12 on Nasdaq. Three mega-IPOs targeting the same institutional investor pool in the same quarter is unprecedented.
One detail that got less attention: Anthropic expanded a ban on secondary share trading ahead of the filing, causing disruption in the pre-IPO market. Companies that had been buying Anthropic shares on secondary markets found themselves locked out. The message was clear: Anthropic controls its cap table now.
The bull case is straightforward. Revenue is growing 5x year over year. Claude Code dominates the AI coding market. Glasswing puts Claude inside critical infrastructure for power grids, water systems, and healthcare networks covering 100 million people. The bear case is equally straightforward. A $15 billion annual compute bill to a single vendor is a concentration risk no public company should carry comfortably. Profitability is projected but not guaranteed. And the IPO market has not yet tested whether public investors will pay trillion-dollar valuations for companies whose core business depends on someone else’s data centers.
Altimeter Capital CEO Brad Gerstner’s quote from the Series H announcement sums up the bull side: “Claude’s latest advancements have driven large-scale adoption among the world’s most demanding organizations. This momentum positions Anthropic to lead the next phase of AI innovation.”
The S-1 review process typically takes 2-4 months. If Anthropic goes public in fall 2026 as Bloomberg projects, it will likely beat OpenAI to the public markets, giving it first-mover advantage in what Fortune calls “the two largest AI listings of 2026.”