Anthropic's Seven Cofounders Each Hold About 240 Million Shares, Worth Roughly $14 Billion at Last Private Price

Anthropic's S-1, filed with the SEC today, Oct. 26, puts exact share counts on the seven people who left OpenAI in January 2021 to start the company. The numbers are very similar.

Tom Brown, the chief compute officer, holds about 244 million shares, the most of any cofounder. Christopher Olah holds 242.9 million, chief science officer Jared Kaplan 242.4 million, and Jack Clark 242.3 million. President Daniela Amodei beneficially owns 241.4 million. CEO Dario Amodei owns 240.6 million and votes another 4.6 million shares under proxy agreements. The remaining cofounder, Sam McCandlish, falls in the same 232 million to 243 million band that covers the six cofounders other than Brown.

What the stakes are worth

The filing has no IPO price and no share count for the offering, so any dollar figure is an estimate.

At $58.90 a share, the split-adjusted price paid in the spring Series H round, each stake would be worth between $13.7 billion and $14.4 billion, according to Fortune's calculation. Together the seven hold about 1.69 billion shares, roughly 10% of the company. At a $2 trillion listing, Fortune puts each stake at $27 billion to $29 billion.

Business Insider ran a lower scenario: at $1.5 trillion, Brown's stake would be worth roughly $24 billion.

The $58.90 figure comes from the filing. Between May and June, Anthropic sold 77.6 million shares of Series H-1 preferred at $589.0095 each, raising $45.7 billion. On Sept. 17 it split its Class A and Class N common stock 10-for-1. Series H buyers got preferred stock with rights common holders lack, so the private price is a rough yardstick for common shares.

The company was valued at $965 billion in May. Wall Street estimates cited by CBS News and the Associated Press put a public valuation at $1.5 trillion or possibly $2 trillion. The final figure has not been set.

Selling shares, with the amounts blank

All seven cofounders are listed as selling stockholders in the offering. The number of shares each plans to sell is left blank.

The ownership table is dated Sept. 30, 2026. Each figure includes 2,185,400 stock options and 639,500 restricted stock units that vest within 60 days. Daniela Amodei's count also includes about 264,500 options and units held by her spouse. Dario Amodei's 4.6 million proxy shares sit in donor-advised funds, so he votes them but no longer owns them.

Benjamin Mann is a notable omission. The filing says he has been with Anthropic since its founding and "is often referred to as a cofounder." But he is not a member of the founders' LLC, the filing says its use of "cofounders" excludes him, and his stake is not in the ownership table.

Control without matching ownership

Each cofounder owns about 1.4% of the company, by Fortune's estimate of roughly 16.9 billion fully diluted shares. Their voting power is far larger. Immediately before the IPO, Anthropic plans to issue a single Class F share to an LLC whose only members are the seven cofounders. That share carries 50.1% of the vote.

Anthropic says the structure gives the founders "the ability to determine the outcome of all matters submitted to a vote of our stockholders generally for the foreseeable future." The filing calls the arrangement a "novel capital and corporate governance structure" with "no direct public company precedent."

The company also concedes the downside in its own words. The structure "is likely to have the effect of limiting the likelihood of an unsolicited merger proposal, unsolicited tender offer, or proxy contest for the removal of directors," and may deprive stockholders "of an opportunity to sell their shares at a premium over prevailing market prices."

Snap's 2017 IPO is the obvious comparison. Evan Spiegel and Bobby Murphy kept about 89% of the vote there. What sets Anthropic apart, Business Insider noted, is seven founders with nearly identical stakes.

The company says the structure protects its AI safety mission. A Long-Term Benefit Trust, set up in 2023, will appoint most of the board.

Investors who back the model say founder control can pay off. Byron Deeter, a partner at Bessemer Venture Partners, told CNBC that for "category-defining, industry-defining opportunities, you want teams to be able to think long term." He said that lets teams "focus on true innovation, and not be month-to-month, or even quarter-to-quarter." Bessemer invested at a $14 billion valuation, and Deeter called it the largest cost-basis investment in the firm's 116-year history.

The business behind the paper wealth

Revenue for the first half of 2026 was $16.3 billion, up from $1.2 billion a year earlier. The company says growth is expected to decline over time. Operating loss was $693 million, against $2.1 billion in the first half of 2025.

The net loss was $80.7 billion, largely from noncash accounting adjustments tied to convertible debt, according to the filing. The company says it may not achieve or sustain profitability.

As of the end of September, Anthropic had more than 11,900 customers spending at least $100,000 a year, 1,900 spending $1 million or more, and about 250 spending $10 million or more.

The filing also sets aside 846.8 million shares, 5% of fully diluted shares as of June 30, for a new Anthropic Public Benefit Fund.

Anthropic plans to list on the Nasdaq under the ticker "ANT." The offering could raise as much as $100 billion, according to reports, which would top the $86 billion SpaceX raised in June. The pricing range, the total shares offered and each founder's sale amount are the figures Anthropic still has to fill in before the stock trades.