Anthropic vs OpenAI, Racing to List at the Same Time — Both Filed Confidential S-1s, and Going First Pays

AI's Two Titans Filed to List in the Same Month

Here's the deal: in June 2026, AI's two giants made the same move a week apart. Anthropic filed a confidential S-1 with the SEC on June 1, and OpenAI on June 8. The S-1 is the first official document toward going public; because these are confidential filings, the contents aren't public yet. Still, the fact that both companies took the first step toward listing almost simultaneously is the biggest news in capital markets.

The scale shows why the market is buzzing. Anthropic is pegged at roughly $965 billion after its $65 billion Series H, and OpenAI is cited near $852 billion. Together that's over $1.8 trillion. Add SpaceX ($1.77T), which debuted on the Nasdaq today, and the three companies' combined valuation reaches about $3.6 trillion — record-scale capital pouring into public markets all at once around AI and space.

The heart of this story is competition. The two aren't just listing around the same time — they're sprinting over who hits the market first, because bankers are advising that there's a first-mover advantage. So June's two S-1 filings read not as a "simultaneous start" but as the starting gun in a race to go first.

The Cast — Anthropic, OpenAI, and the 'First-Mover Advantage'

The first lead is Anthropic, which filed first on June 1. What stands out is revenue growth. As of May 2026 its annualized revenue run-rate (ARR) was about $47 billion, exploding from roughly $10 billion a year earlier — more than 4x in a year. That steep curve underpins the $965 billion valuation. Filing first also reads as being a step ahead in the first-mover race.

Second is OpenAI, which filed a week later on June 8. It has the highest public name recognition thanks to ChatGPT, but in the listing race it looks a step behind Anthropic. That said, OpenAI's overwhelming user base and brand power mean it could draw the most retail interest when it actually lists. The tension between "No. 1 in recognition" and "No. 2 in filing order" is the intriguing part.

The third character is abstract but is the engine of this race: the first-mover advantage. When several similar companies try to list around the same time, the one that goes first absorbs the market's money and attention first. Investor wallets are finite, so if capital crowds into the first mega-IPO, those that follow can be relatively disadvantaged. That's why both companies have a strong incentive to go first.

The Core — The IPO Trio by the Numbers

Company	S-1 filed	Valuation	Note
Anthropic	2026-06-01	~$965B	May ARR ~$47B (from ~$10B a year ago)
OpenAI	2026-06-08	~$852B	No. 1 in public recognition via ChatGPT
SpaceX	(already listed)	~$1.77T	Nasdaq debut June 12 (SPCX)
Combined	—	~$3.6T	Record-scale IPO wave

The table isn't just three listings — it's a giant wave entering public markets at the same time, at record scale, on the same theme (AI and space). One such listing would be huge; three companies worth around $1 trillion each lining up weeks apart means overall market liquidity and sentiment can't help being swayed by this wave.

It's worth noting what a "confidential S-1" means. A confidential filing is the stage where a company starts listing prep but hasn't yet disclosed financials to the public. It exchanges reviews privately with the SEC, then releases a public version and starts the roadshow as the listing nears. So June's two filings only signal "they're at the starting line" — actual listing (trading) is expected in the second half of 2026. Right now it's the race's start line.

Who Gains What

For Anthropic, the biggest win is going first. If the first-mover advantage truly works, Anthropic secures the market's money and attention first and buys time to sell investors on its explosive ARR story. The title of "the AI company validated in public markets before OpenAI" is valuable for the brand too. But going first also means being the first test of market sentiment.

For OpenAI, the card is "later but bigger." ChatGPT's overwhelming user base and recognition are powerful tools for drawing retail subscription demand. If Anthropic warms the market by going first, OpenAI could list at even greater scale on that heat. It may trail in order but lead in firepower — which is why the two have subtly different calculations.

For investors and capital markets, multiple large windows to bet directly on AI open at once. Until now, riding the AI boom meant infrastructure stocks like Nvidia or investing indirectly through Big Tech. Now a path opens to invest directly in pure AI-model companies like Anthropic and OpenAI. Just note that if all three absorb huge capital at once, it could strain market liquidity and affect other tech stocks.

History — Simultaneous IPO Waves, Hits and Bubbles

The success template is the big tech IPOs after dot-com. When markets fell in love with a theme, that theme's flagship companies listed in a row, raised vast capital, and lifted whole industries. If AI is truly the next industrial revolution, the simultaneous listings of Anthropic, OpenAI, and SpaceX could be recorded as the historic turning point where capital flowed into it in earnest.

The cautionary side is just as clear. When money overheats around a theme, "bubble IPOs" where expectation outruns fundamentals get mass-produced, and disappointment selling floods in on day one or just after. Simultaneous listings amplify the risk: if even one of the three has a weak debut, "AI bubble" talk can spread to the whole trio. That's why today's SpaceX first trading day matters even more — it's the first scorecard of this wave.

The lesson: a simultaneous IPO wave is a strong signal that "the market sees the theme as the next engine," but it also carries the risk of expectation racing ahead of results. To justify valuations near $1 trillion, Anthropic and OpenAI must prove it with actual revenue and profit after listing. Explosive ARR is a good start, but public markets scrutinize the "path to profitability" as much as growth.

Rivals' Counter-Play

Big Tech like Google, Meta, and Microsoft are already public, so they're not in the direct IPO race — but they compete indirectly on the stage of share prices. When pure AI plays (Anthropic, OpenAI) list, investors weigh "Big Tech's AI business vs. pure AI companies." Big Tech's counter is a stability message — "we run AI on top of an already enormous profit base" — to differentiate from the pure plays' high valuations and high risk.

For other AI startups, this race is a benchmark. The valuation and story with which Anthropic and OpenAI succeed will shape the funding environment for AI companies that follow. If the trio's listings go well, later AI companies can raise on better terms; if they stumble, AI funding overall could freeze. That's why the whole industry watches this race with bated breath.

Ultimately the big picture is how public markets price AI. In private markets, a handful of investors set valuations; in public markets, countless investors vote in real time. Anthropic and OpenAI are getting that first public grade, and the result will redefine the capital environment for the entire AI industry.

So What Actually Changes — By Audience

For investors, the core point is that several options to bet directly on AI are coming soon. But at the confidential-S-1 stage, actual listing and subscription are expected in the second half, and valuations near $1 trillion already carry plenty of expectation. It's best to hold both the big picture ("bet on AI's future") and the cool question ("is that price reasonable?").

For people and founders in AI, this race is a weathervane for your company's and the industry's funding environment. If the trio's listings succeed, more money flows into AI overall; if they stumble, the funding mood cools. It's worth checking your company's capital plans against this wave.

For general observers, grab the picture that AI has now entered the heart of capital markets. AI used to live in tech news, but with Anthropic, OpenAI, and SpaceX listing at once, it's now a protagonist of the stock market. An era is opening where AI's success ties directly to the assets of countless investors, not just technology.

🥄 Three Things You're Probably Wondering

— So can I buy Anthropic or OpenAI stock? Not yet. Both are at the confidential-S-1 stage, so actual trading is expected in the second half of 2026. A public S-1, roadshow, and subscription have to come first before retail can buy. Right now it's the "started listing prep" signal stage.

— Why are they both rushing at the same time? Because bankers advise there's a first-mover advantage. Investor money and attention are finite, and the first mega-IPO absorbs them first. So both have a strong incentive to "go before falling behind."

— $3.6T combined? Can the market absorb all that? Too early to call. Record-scale capital entering public markets at once can strain liquidity. If even one of the three has a weak debut, the mood could cool; if all succeed, it'll signal the dawn of an "AI capital era." Today's SpaceX first day is the first gauge.

References

• Anthropic Files Confidential S-1 — Fortune
• OpenAI makes IPO decision amid Anthropic, SpaceX fervor — TheStreet
• OpenAI confidentially files for IPO, prepping Wall Street for AI debut — CNBC
• Anthropic Files Confidential S-1, Joins AI IPO Wave — Yahoo Finance

Numbers and criteria are as of announcement and may change. Investment calls are yours to make!