OpenAI Files Confidentially for IPO, One Week After Anthropic

One week after Anthropic submitted its draft S-1 to the Securities and Exchange Commission, OpenAI did the same. The parallel filing, confirmed June 8, means both of the world's most closely watched AI companies are now in the SEC's review queue at the same time, each targeting the same fall listing window.

What OpenAI Filed

OpenAI submitted a confidential draft registration statement on Form S-1 to the SEC on June 8. The number of shares and the offering price were not disclosed; those details come after the SEC completes its review and the company decides when to move. OpenAI was most recently valued at approximately $852 billion post-money in its latest private funding round.

Confidential filings are standard for large IPOs. The company can work through the SEC's comments privately, revise the document, and then choose its moment to make the prospectus public. Until that public filing, most of the financial details — revenue, margins, customer concentration, compute spending — remain undisclosed.

What Anthropic Filed First

Anthropic's filing, one week earlier, followed the close of its $65 billion Series H round co-led by Altimeter Capital, Dragoneer, Greenoaks, and Sequoia Capital. That round set a post-money valuation of $965 billion, and the company disclosed at the time that its annualized revenue reached $47 billion in May 2026, up from roughly $10 billion at the end of 2025.

The speed of Anthropic's revenue growth has been central to its IPO narrative. Quarterly revenue figures, gross margins, and the balance between consumer subscriptions and enterprise API contracts are the numbers prospective investors will study most closely. Analysts briefed on the company's trajectory expect the S-1 to show strong enterprise concentration, particularly in legal, financial services, and software development, with Claude Code's rapid adoption as a key growth driver.

"It's a very capital-intensive business to train AI models. The sort of core set of companies working to advance the frontier are just going to need access to capital, and I think the public market is very well suited to that." Daniela Amodei, Bloomberg Technology Summit, June 4, 2026

Why Both Are Filing Now

The decision by both companies to file within a week of each other reflects shared economics as much as competitive posture. Training frontier AI models is capital-intensive in ways that private venture rounds alone are increasingly inadequate to fund. Anthropic has said publicly that the scale of compute required for next-generation models makes continuous access to public capital markets the most reliable long-term funding structure. OpenAI has made a comparable argument.

Public markets offer something private funding does not: the ability to raise repeatedly, in size, without negotiating new share classes or dilution terms with existing investors each time. For companies whose capital needs are measured in tens of billions per year, that flexibility matters operationally, not just financially. For both Anthropic and OpenAI, the race to public markets is also a race to establish brand recognition with a retail investor base that will follow AI quarterly results for years.

What the Race Means

Analysts have noted that whichever company lists first will likely benefit from more favorable conditions, partly because investor appetite for AI exposure is high, and partly because the second listing will be compared against the first at every point in the roadshow. Anthropic's one-week lead in the filing process does not guarantee a one-week lead in the listing itself. The SEC review period varies, and both companies may hold back for a favorable market window regardless of their filing sequence.

The dual filing also sets up a novel regulatory moment. Both companies are subject to AI governance frameworks still being finalized in the United States and Europe. Going public will require each to make explicit disclosures about their models' risks, safety testing processes, and regulatory exposure in language that is legally accountable rather than optional. The SEC has signaled that AI-specific risk disclosures are an area of active focus, which means the prospectuses from these two companies could set precedent for how frontier AI businesses characterize model risk to investors.

Neither Anthropic nor OpenAI is profitable in the traditional sense; both are spending heavily on compute, safety research, and operations. The bull case for each rests on the same premise: that Claude and ChatGPT respectively are on revenue trajectories that justify multiples of current run rates, and that the infrastructure investment required to sustain them is front-loaded rather than perpetual. Investors who accept that premise are the audience both companies are now courting.

For Anthropic, the public filing will mark the end of an era of private-market opacity. Once the S-1 goes live, the company's revenue mix, customer concentration, cost structure, and safety expenditures become visible to anyone. That transparency is a new kind of accountability — and for a company that has consistently argued its commercial success and its safety mission are complementary, a new kind of public test.