OpenAI submitted a confidential S-1 registration document to the Securities and Exchange Commission, the company confirmed Monday, setting the stage for a potential public offering as early as the fourth quarter of 2026. The company is working with Goldman Sachs and Morgan Stanley on the filing – the same two banks leading SpaceX’s roadshow, which kicked off last week. Anthropic made an identical move seven days earlier.
OpenAI did not wait for news of the filing to surface on its own. In a post on its website, the company acknowledged it expected the document to leak and chose to announce it directly. “We have not decided on timing yet,” the statement read, noting that some planned steps may be easier to execute while the company remains private and that a listing could still be some time away.
At its most recent funding round in late March, OpenAI was valued at $852 billion. That figure now trails Anthropic, which closed a Series H round shortly before its own IPO announcement at a $965 billion valuation. The reversal is notable given that OpenAI has long held the position of the most valuable private AI company and has raised more than $180 billion in total funding. The company remains cash-negative as it continues to spend heavily on computing infrastructure and model training.
To ease near-term pressure on employees and early investors, OpenAI plans to run a tender offer allowing staff to sell shares at the current $852 billion valuation, according to a person familiar with the arrangement who was not authorized to speak publicly.
ChatGPT now serves more than 900 million weekly active users, a figure that underscores the scale of the company’s consumer reach. Internally, OpenAI has been narrowing its product focus – shutting down peripheral efforts including its Sora short-form video application – and directing capital toward enterprise contracts and Codex, its AI coding assistant, which competes with Anthropic’s Claude Code. In an April post, CEO Sam Altman described Codex as having a “ChatGPT moment.”
Three Companies, One Window
The convergence of three major AI-related listings within weeks of each other is without precedent in the sector. SpaceX’s offering, seeking to raise up to $86 billion at a $1.78 trillion valuation, is already in active roadshow. Anthropic and OpenAI are at earlier stages, with both filings confidential and no pricing announced. All three companies list each other among primary competitors in their respective filings – OpenAI, Anthropic, and Google are named explicitly as rivals in SpaceX’s S-1.
Whether the market can absorb three high-valuation, cash-intensive AI offerings in close succession is the central question facing underwriters. Each company’s reception may directly influence the others. A strong SpaceX debut would build appetite; a weak one could prompt Anthropic and OpenAI to extend their timelines.
Altman’s Third Act – and Musk’s Shadow
Alongside the IPO announcement, Sam Altman published a post framing what he called the third phase of OpenAI’s development. The first was foundational research toward artificial general intelligence. The second was building a consumer product business. The third, he wrote, is about making advanced AI accessible, affordable, and useful at a scale that reshapes the broader economy.
The announcement lands less than a month after Altman and Elon Musk concluded a three-week federal trial. Musk, who originally sued OpenAI and Altman in 2024 over allegations that the company abandoned its nonprofit founding mission, lost the case on procedural grounds when an advisory jury found he had waited too long to bring his claims. The federal judge adopted that verdict immediately. Musk disputed the outcome, characterizing it as a ruling on timing rather than the substance of his argument.
Musk’s SpaceX – which merged with his AI company xAI earlier this year – now competes directly with OpenAI in the AI market at the same moment both are attempting to raise public capital. The two men’s companies will be asking the same pool of institutional investors to back competing visions of where AI goes next.
