On June 1, Anthropic did something unexpected. The company that built Claude — the chatbot that just dethroned GPT-5.5 on key benchmarks — confidentially submitted a draft registration statement to the U.S. Securities and Exchange Commission. That's Wall Street speak for "we filed for an IPO." And they did it just four days after dropping Claude Opus 4.8.
OpenAI, the company Anthropic was founded to compete with, wasn't even in the building. CEO Sam Altman said Monday that he's "not focused on the timing" of an IPO. Prediction markets had OpenAI as the favorite to file first. Anthropic just flipped that script. This wasn't a coincidence. This was a power move.
The $965 Billion Question
Let's talk about what Anthropic is bringing to the table, because the numbers are genuinely absurd. Just before filing, Anthropic closed a $65 billion Series H round led by Altimeter Capital, Dragoneer, Greenoaks, and Sequoia Capital. The post-money valuation: $965 billion.
That makes Anthropic the most valuable private AI company in the world. For the first time, it's ahead of OpenAI, which was last valued at $852 billion in March. Nine hundred and sixty-five billion dollars for a company that, until recently, was considered the "safety-first" runner-up to OpenAI's flashy dominance. The math alone is worth pausing over.
The Revenue Story No One Saw Coming
Here's where things get interesting. Anthropic's annualized revenue run rate hit $47 billion in late May, according to reports. That's up from $14 billion in February — a more than threefold jump in under four months. OpenAI's run rate, by comparison, sits around $33 billion.
The driver appears to be Claude Code, the company's AI-powered coding assistant. Just one product was already generating $2.5 billion in annualized revenue back in February. Enterprise customers are plugging Claude directly into their workflows, and usage is exploding. But here's the number no one outside Anthropic has ever seen: gross margin.
PitchBook senior analyst Harrison Rolfes put it bluntly. "The number that determines everything is not the $965B valuation or the $47B revenue run rate — it is gross margin, which no one outside Anthropic has ever seen, and which will either validate or collapse the entire narrative the private markets have been pricing for three years." In plain English: we're about to find out if this business actually works.
Why Now? The IPO Window Is Closing Fast
Anthropic isn't just racing OpenAI. It's racing SpaceX, and the window is closing fast. SpaceX is targeting a Nasdaq listing around June 12, aiming to raise at least $75 billion at a valuation of roughly $1.8 trillion.
The IPO market is already the hottest it's been since 2021. Global IPO proceeds hit $87.5 billion through May 26, the highest level in five years. But there's only so much capital to go around. "SpaceX will consume an enormous amount of capital, and the second person in the door has a better position than the third," said Patrick Healy, founder of Issuer Network.
D.A. Davidson analyst Gil Luria agreed. "The combined capital needs of SpaceX, OpenAI, and Anthropic will be very large and will likely disrupt the capital markets, so going public sooner will be a significant advantage." Anthropic clearly got the memo. By filing now — potentially aiming for a fall 2026 listing — it's trying to get ahead of the crowd.
The OpenAI Angle: Genius or Excuse?
Here's where the story gets genuinely interesting. Rolfes offered a counterintuitive take that's worth quoting at length. "The unconventional read is that OpenAI got the better end of this — Anthropic just volunteered to absorb all the disclosure risk first, and OpenAI now has a free option to watch how institutional investors react to audited frontier AI financials before committing to its own price."
Think about that logic. If Anthropic's margins disappoint, OpenAI restructures its story quietly before its roadshow. If the deal is oversubscribed, OpenAI rides the wave with a tailwind and no downside. In other words, Anthropic is the guinea pig. The market will either love what it sees or hate it. OpenAI learns for free either way.
That's either brilliant strategy from Altman — or a convenient excuse for being late. Either way, Anthropic just made the first move.
The Risks No One Is Talking About
Anthropic's S-1 will reveal things the company has never had to disclose before, and not all of them will be pretty. The company pays Amazon and Google for cloud infrastructure. A lot. The exact terms of those revenue-sharing agreements will become public, and investors will scrutinize every percentage point.
Anthropic is also currently in a legal battle with the U.S. government. It was flagged as a supply chain risk by the Pentagon — partly over refusal to remove certain safety restrictions from its contracts with the Department of Defense. That's not the kind of headline you want heading into a roadshow.
And while reports suggest Anthropic is on track for its first operating profit in the June quarter — an estimated $559 million on roughly $10.9 billion in quarterly revenue — those numbers could shift once the full S-1 is public. With AI infrastructure spending only accelerating, maintaining profitability while scaling is no small feat.
The Bigger Picture: An AI IPO Supercycle
Anthropic's filing isn't happening in a vacuum. You've got SpaceX targeting a June 12 listing. You've got OpenAI, expected to file its own confidential S-1 in the coming weeks. And you've got Anthropic, now officially in the pipeline.
Wedbush Securities analyst Dan Ives called it "an opening of the floodgates for the IPO market, which has been relatively dormant for a few years, with these three major conglomerates set to go public later this year." But here's the catch: the last time we saw a tech IPO wave this concentrated, it was the dot-com era. And we all know how that ended.
Rolfes put it more elegantly. "The 2026 window either becomes the most consequential IPO cycle since the dot-com era or the most expensive lesson in narrative-versus-fundamentals that public markets have ever taught."
What Happens Next
Anthropic's confidential filing means the clock has started. The company can now work through SEC comments privately, without revealing sensitive financials to competitors or the public. The formal prospectus — the one everyone actually wants to read — will need to be filed at least 15 days before the roadshow begins.
That's when we'll find out the real story. The gross margins. The cloud costs. The customer concentration. The government contracts. Everything Anthropic has kept private for five years will, eventually, become public. And that's when Wall Street will decide whether $965 billion was a bargain — or a bubble.
P.S. If you're keeping score at home: Anthropic just dropped a new model, raised $65 billion, and filed for an IPO — all in the same week. Sam Altman says he's "not focused on timing." One of these companies is lying. The other is about to go public.
