Anthropic’s two-part IPO lockup lets insiders sell early, breaking with SpaceX and Cerebras

Anthropic’s IPO lockup lets insiders sell early, breaking with the SpaceX and Cerebras playbook

Anthropic has filed an S-1 registration statement with the SEC for a Nasdaq listing under the ticker ANT, with a two-part share-sale structure that departs from the single 180-day lockup of recent mega-IPOs: limited secondary sales by existing shareholders during the offering itself, and lockups on the remaining pre-IPO shares that could stretch into mid-2027.

Some early investors and employees would be allowed to sell before the standard 180-day lockup ends, and the company is considering Rule 10b5-1 trading plans that let insiders sell on a pre-set schedule. Secondary-sale proceeds go to the sellers, not to Anthropic’s balance sheet.

The contrast with recent technology listings is direct. SpaceX and Cerebras did not permit secondary sales in their IPOs, keeping existing holders out of the offering entirely. Anthropic’s structure brings early sellers in while holding other holders back longer, and it will shape how the float of a very large listing behaves in its first months.

The filing caps a year in which Anthropic’s market footprint has already crossed into crypto-adjacent industries: the company is the same Claude maker behind a reported $9 billion AI compute deal with Riot Platforms.

The lockup detail arrives alongside scale that raises the stakes for whoever holds shares. Valuation discussions for the offering center on a range of $1.5 to $2 trillion depending on market conditions, and reports suggest the company could raise up to $100 billion. The filing follows a confidential draft registration submitted on June 1, with a listing possible as soon as mid-November.

How large the secondary allocation will be, and which shareholders qualify, are not disclosed.