Anthropic Files Confidential S-1 as $965 Billion Valuation Fuels Historic IPO Race

Anthropic filed a confidential S-1 with the SEC on June 1, 2026. That’s not a drill — the Claude maker is officially in the IPO queue, right alongside SpaceX and OpenAI, and the numbers behind all three are staggering.

The filing came under Rule 135 of the Securities Act of 1933, which gives Anthropic breathing room to move forward once the SEC finishes its review. Share count and price? Not set yet. The company says both are contingent on market conditions, which is pretty standard language for a confidential filing but tells you they’re not rushing to lock anything in before the regulatory process plays out. What is locked in: a $65 billion Series H funding round that pushed Anthropic’s post-money valuation to $965 billion. Annual revenue run-rate has cleared $47 billion, driven almost entirely by enterprise demand for Claude models — companies using AI for coding, workflow automation, and back-office tasks at scale.

That’s a lot of zeros.

SpaceX and OpenAI Already in Motion

Anthropic isn’t first. SpaceX filed a public S-1 on May 20, targeting a Nasdaq listing with an expected valuation somewhere between $1.75 trillion and $1.8 trillion. If that range holds, SpaceX would raise roughly $75 billion — potentially the largest IPO in market history. OpenAI filed confidentially around May 22, aiming for a September debut at a valuation north of $1 trillion. So within roughly ten days, three of the most talked-about private companies in the world all moved toward going public. That’s not a coincidence. It’s a window, and all three are trying to climb through it.

For investors, the appeal is obvious. Exposure to AI and space tech at this scale simply hasn’t been available in public markets before. But it’s worth being clear-eyed: these companies carry massive operational costs, face real competition, and will now have to answer to quarterly earnings cycles and public shareholders in ways they never did as private firms.

That’s a different kind of pressure.

Anthropic’s Compute Commitments and Big-Tech Ties

One number that keeps jumping out of Anthropic’s financial picture: $1.25 billion per month. That’s what Anthropic is paying SpaceX for AI compute capacity, locked in through May 2029. So Anthropic is simultaneously a competitor in the IPO race and a paying customer of SpaceX — which is a strange dynamic, but probably reflects just how capital-intensive this industry has become. You need compute. Lots of it. And right now, the supply is tight enough that Anthropic is committing more than a billion dollars a month to secure it.

Partnerships with Amazon and Google round out the picture. Both tech giants have made substantial commitments to Anthropic, backing it with cloud infrastructure and investment that helped fuel the Series H round. It’s basically a bet by two of the world’s largest companies that Anthropic’s Claude models stay relevant — and that the enterprise AI market keeps growing fast enough to justify the spend.

The compute deal with SpaceX, the Amazon and Google partnerships, the $47 billion revenue run-rate — none of that happened overnight. Anthropic has been building toward this for a while, and the S-1 filing is the clearest signal yet that the company thinks the public market is ready for it.

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Or maybe that it can’t wait much longer.

What the IPO Wave Means for AI Markets

There’s a broader shift happening here. For years, the most exciting AI companies stayed private, raising enormous rounds from venture capital and sovereign wealth funds while keeping their financials away from public scrutiny. That era seems to be ending. Anthropic, OpenAI, SpaceX — these aren’t small bets. A combined potential market cap in the multiple trillions would reshape how index funds, pension managers, and retail investors allocate capital toward technology.

And it changes the accountability structure entirely. Private companies can miss targets quietly. Public companies can’t. Earnings calls, analyst coverage, short sellers — all of that kicks in the moment the stock starts trading. Anthropic’s Claude models have strong enterprise traction now, but sustaining $47 billion in annual run-rate revenue while navigating regulatory scrutiny, model competition, and the cost of GPU capacity is a different challenge than growing fast in a private setting.

SpaceX’s roadshow is approaching. Anthropic and OpenAI are advancing toward their own listings. The timing feels coordinated even if it probably isn’t — more likely, all three companies looked at the same market window and made the same call.

Unclear yet whether any of them will hit their target valuations when shares actually price. Markets can move fast, and investor appetite for trillion-dollar AI companies at these multiples hasn’t really been tested in a public setting before.

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What’s not unclear: Anthropic’s $1.25 billion monthly compute bill keeps running regardless of how the IPO goes.