OpenAI Files Confidential IPO Paperwork, Following Anthropic by a Week
OpenAI confidentially submitted a draft S-1 registration statement to the Securities and Exchange Commission on June 8, 2026, the company confirmed in a post on its own site and on X (OpenAI, CNBC). It is the first formal step toward a public listing for the company, and it lands exactly one week after Anthropic made the identical move.
Neither company has set a timeline. But two of the three most valuable AI labs in the world now have paperwork in front of regulators, and that changes what "funding round" means for the sector going forward.
Anthropic moved first
Anthropic confidentially submitted its own draft S-1 on June 1, 2026, the company said in a post on its site (Anthropic). The filing follows a $65 billion Series H round that closed in late May at a $965 billion post-money valuation, according to reporting on the round (Yahoo Finance).
Anthropic disclosed run-rate revenue of $47 billion as of its May 28 Series H announcement, up from $9 billion in December 2025 (Simon Willison's analysis of the disclosure). Much of that growth is attributed to Claude Code, the company's agentic coding product, whose business subscriptions were reported to have quadrupled since the start of 2026. Anthropic has not said when, or whether, it will actually list shares. Both filings are confidential, meaning the underlying financials are not yet public.
OpenAI's filing follows its largest round to date
OpenAI's S-1 comes three months after it closed a $122 billion funding round at an $852 billion valuation on March 31, 2026, the largest private financing round on record (Bloomberg, CNBC). Amazon put in $50 billion, with Nvidia and SoftBank each contributing $30 billion, according to the same reporting. A portion of Amazon's commitment, $35 billion, is contingent on OpenAI either going public or reaching a defined technological milestone specified in the deal.
OpenAI said in its own announcement that it expects the confidential filing to leak and that no decision on timing has been made: there are things it wants to do that are likely easier as a private company, but the filing gives it the option to go public sooner if that ends up being best (OpenAI). The company is working with Goldman Sachs and Morgan Stanley on the draft registration, per reporting from Fortune (Fortune).
What changes for enterprise buyers
For enterprise buyers, the practical effect is limited for now. Confidential S-1 filings do not require public financial disclosure and do not commit either company to a listing date. Anthropic's process is reportedly targeting an October 2026 window, though the company has stressed that market conditions could change that.
What the filings do signal is that both labs are preparing the audited financial infrastructure a public listing requires, at the same time their private valuations have outpaced almost every prior technology financing. A company approaching $47 billion in annualized revenue and a $965 billion valuation, or an $852 billion valuation on the back of a $122 billion round, is being asked by its own investors to show the kind of financial transparency that private capital alone no longer forces. Amazon's contingent $35 billion stake, tied explicitly to an OpenAI listing, is one concrete example of that pressure showing up in deal terms rather than commentary.
What to watch next
Anthropic's confidential filing points toward a possible October Nasdaq listing, per current reporting, though the company has not confirmed a date. OpenAI has given no target window at all. The next concrete marker for either company will be whether one of the draft S-1s converts to a public filing, which happens only when a company is closer to actually pricing shares. Watch for that conversion, not for further funding-round headlines, as the signal that a listing has moved from optionality to plan.
Sources: OpenAI: Confidential submission of draft S-1 to the SEC · CNBC: OpenAI confidentially files for IPO · Fortune: OpenAI files confidential SEC S-1 paperwork for IPO · Anthropic: Anthropic confidentially submits draft S-1 to the SEC · Yahoo Finance: Anthropic Files Confidential S-1 · Bloomberg: OpenAI Valued at $852 Billion · Simon Willison: Anthropic's run-rate revenue hits $47 billion