Anthropic IPO Could Come in September, But It Has a Massive Risk Factor

Anthropic plans to let early investors and staff sell stock in its upcoming market debut, according to a recent report by The Information. SpaceX gave its own backers no such option in June.

The prospectus should land soon after Labor Day on September 7. That document sets out the risks and the finances before anyone can buy.

Anthropic IPO Departs From Musk’s SpaceX Structure

Big listings can sell two kinds of stock:

• New shares raise money for the company.
• Existing shares pay early backers instead.

SpaceX sold only the first kind. Its pricing release covered 555,555,555 new shares at $135 each. Not one came from an existing holder.

Underwriters then took another 83,333,333. That brought the total to 638.9 million shares and roughly $86 billion, still the largest listing ever.

Every dollar went to the company, with the filing estimating that Musk kept about 82.4% of the voting power once trading began.

Anthropic has copied part of that design, as indicated in a recent report. As BeInCrypto reported, it described supervoting shares for founders, the same tool Musk used to hold control.

Letting insiders sell changes the other half:

• Backers get cash at the offer price.
• Buyers absorb more stock on day one.

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Longer Lockups Could Offset the Early Selling

A lockup bars insiders from selling for a set period after a debut. It shields a young stock from a flood of supply. SpaceX shows what the delay looks like, because on August 6, about 911.5 million insider shares became sellable at once. That topped the 638.9 million sold in June.

IN 16 DAYS, $116B OF SPACEX STOCK BECOMES SELLABLE FOR THE FIRST TIMEOn August 6, restrictions lift on as many as 911.5 million insider shares, per Bloomberg, two days after the company's first earnings report. And that is only the opening wave.The schedule:– Tradeable… pic.twitter.com/bBCIMdaRQx

— IPO Newsroom (@IPONewsroom_) July 21, 2026

The tradable pool more than doubled overnight, rising from 4.9% of the company to 11.8%. The stock still closed up 6.1% that day.

Anthropic appears to want the smoother path. A sale inside the deal is priced and placed with buyers in advance. A lockup expiry is neither.

The company is weighing lockups longer than the norm. Insiders would take cash early, then wait longer for a second window.

ANTHROPIC COULD GO PUBLIC AS SOON AS NEXT MONTHAnthropic plans to unveil its IPO prospectus after Labor Day, with a potential listing in late September or early OctoberAlso considering letting existing shareholders sell stock in the IPO while using longer-than-usual lockups… pic.twitter.com/NPSFdgbcGh

— Wall St Engine (@wallstengine) August 27, 2026

The backers in line are also large, given Anthropic raised $65 billion in May at a $965 billion valuation, according to its own announcement. Altimeter, Dragoneer, Greenoaks and Sequoia led that round.

Sovereign money joined too, with Singapore’s state fund GIC co-leading alongside Capital Group and Coatue. Those are the names that would be selling.

They would sell at a far higher price, as Anthropic last reported revenue in May, when it said its run rate had exceeded $47 billion. It has not updated that number since.

The prospectus would answer some of these questions. It is also expected to name public backlash against AI as a formal risk.

Crypto traders already price the same stake. Anthropic exposure trades through pre-IPO token markets on Solana, where PreStocks handles 78% of OpenAI and Anthropic volume.

The filing will probably name who sells and for how much, with the list likely to reveal more about Anthropicis valuation.