Anthropic confidentially submitted a draft S-1 registration statement to the Securities and Exchange Commission on June 1, and rival OpenAI followed suit on June 8, putting both leading AI labs on parallel paths toward a potential IPO.
The filings arrive as AI valuations and revenue have both exploded. Anthropic's confidential submission came just days after it closed a $65 billion Series H round that pushed its private valuation to roughly $965 billion, with a debut above $1 trillion viewed as a base-case scenario if markets hold up. OpenAI, previously valued near $852 billion, said in its own announcement that it expects the filing 'to leak' and hasn't decided on timing, since 'some things are easier to do as a private company.'
What happened
Anthropic's Form S-1 was submitted under Rule 135 of the Securities Act of 1933, a mechanism that lets late-stage companies begin the IPO review process without immediately disclosing revenue, margins or risk factors to the public. The company said the filing 'gives us the option to go public after the SEC completes its review,' with the number of shares and price still undetermined. Anthropic's revenue run rate has climbed to roughly $47 billion, up from $10 billion in annual revenue a year earlier, and the company says Claude now captures 70% of Fortune 100 paid-AI adoption, with Claude revenue up 75% since January.
OpenAI's confidential filing followed one week later. The company is also pushing forward on the product side: it began a limited preview of GPT-5.6, offered in three variants — Sol, Terra and Luna — with stronger reasoning, coding, biology and cybersecurity performance and a new 'ultra mode.' GPT-5.6 Sol set a new state-of-the-art on Terminal-Bench 2.1, a benchmark for command-line agentic workflows, and matched competitive cybersecurity vulnerability-research results using roughly a third of the output tokens of a leading rival system.
Why it matters
Both companies are racing to go public while AI infrastructure spending faces growing scrutiny. Anthropic is expanding aggressively, opening a Seoul office and announcing Korean AI partnerships on June 17, while preparing an upgraded Opus model line focused on coding and long-running agentic tasks. It has separately accused Alibaba of running what it calls the world's largest AI 'distillation' attack, alleging 29 million Claude exchanges were routed through 25,000 fraudulent accounts, and sent a letter on the matter to U.S. senators and the White House.