Anthropic’s S-1 was filed with the SEC on 26 October 2026. It says the company contributed 846,840,960 shares of its Class N common stock to Anthropic Public Benefit Fund, LLC, a wholly owned subsidiary, “representing 5 % of our fully diluted shares as of June 30, 2026 (assuming full conversion of the Amazon Notes, as defined below)”.
The same filing’s ownership table lists each of the seven co-founders with between 231,809,780 and 244,173,040 Class A shares as of 30 September 2026. The fund’s block is 3.5 times the largest of those stakes, by our arithmetic.
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The key insight: As we read it, the S-1 puts the largest single block named in its ownership disclosures in a fund Anthropic owns: 846,840,960 shares, 3.5 times any co-founder’s stake, by our arithmetic.
The table gives Tom Brown 244,173,040 Class A shares, Christopher Olah 242,882,420, Jared Kaplan 242,351,170 and Jack Clark 242,271,840. It gives Daniela Amodei 241,408,940, Dario Amodei 240,637,980 (245,259,100 including 4,621,120 shares under voting proxies) and Sam McCandlish 231,809,780. The counts include options and RSUs that vest within 60 days, as the table’s rules set out.
Dividing the fund’s 846,840,960 shares by 5% implies about 16.94 billion fully diluted shares at 30 June, by our arithmetic. On that base each co-founder holds between 1.37% and 1.44%, and the seven together hold 1,685,535,170 shares, about 10%, twice the fund. The two counts are from different dates, 30 June and 30 September, so the percentages are approximate.
Bloomberg reported on 27 October that the seven co-founders “each hold roughly 1.4% of the company”, which matches that arithmetic. The S-1 itself leaves its percentage columns blank. The filing also says the co-founders “have each pledged to dedicate 80% of their personal equity in Anthropic to philanthropic causes.”
Shares held per Anthropic’s S-1: the Anthropic Public Benefit Fund’s 846,840,960 Class N shares (5% of fully diluted shares at 30 June 2026) against each co-founder’s Class A shares at 30 September 2026. 3.5x is our arithmetic. Source: Anthropic’s S-1.Anthropic’s S-1: the Anthropic Public Benefit Fund holds 846.8 million Class N shares (5% of fully diluted shares at 30 June 2026); the largest co-founder stake is 244.2 million Class A shares (30 September 2026); 3.5x is our arithmetic; the Founder LLC’s Class F share carries 50.1% of the vote after the IPO.
Amazon and Google Are Not in the Table
The Anthropic Public Benefit Fund’s 846.8 million shares against the largest co-founder stake, Tom Brown’s 244.2 million; circles to scale by area; 3.5x is our arithmetic. Source: Anthropic’s S-1.
The ownership table covers holders of “more than 5% of the outstanding shares of any class of our voting securities”, and the rows it lists in that section are the Long-Term Benefit Trust, with one Class T share, and the Founder LLC, with one Class F share carrying 50.1% of the votes after the offering.
Amazon and Google sit elsewhere in the filing. The S-1 says that after its preferred stock and convertible notes convert, “Amazon and Google will each hold greater than five percent of our outstanding capital stock”, in Class N shares, which are non-voting. It leaves their share counts blank.
Outside Holders Named Today
CNBC ran a 27 October segment titled “Anthropic is Altimeter Capital’s largest investment in private fund, says partner Pauline Yang”. Bloomberg reported that the IPO “may give Commonwealth Bank of Australia an opportunity to cash in on a stake it purchased in the artificial intelligence startup more than a year ago.” Neither gives a share count in the text we read.
Spark Capital’s Yasmin Razavi is a director. The table excludes the shares held by Spark Capital funds from her row, and the S-1 says she “expressly disclaims such beneficial ownership.”
Connecting the Coverage
On 26 October we reported each co-founder’s share count and that each can rank up to 10 secret successors; today that piece added Bloomberg’s 1.4% figure and the trustees’ $400,000 annual pay.
And we reported that SK Telecom rose 4.99% on the filing. SK Telecom is an early investor; its own 20-F describes a $100 million investment in Anthropic in 2023.
The Structural Read
As we read it, the voting table and the economic picture are different maps: the table covers voting securities, so Amazon and Google, which the S-1 says will each hold more than five percent in non-voting Class N stock, do not appear in it.
As we read it, the co-founders’ control does not rest on their shares: the S-1 gives the Founder LLC one Class F share carrying 50.1% of the vote, while their Class A stakes come to about 10% of the implied fully diluted count, by our arithmetic.
As we read it, the dollar size of every stake is still open: the S-1 leaves the IPO price range and the percentage columns blank, so any valuation of these holdings is an outlet’s estimate, not a filing figure.
Anthropic, PBC, Form S-1, Our Commitment to Public Benefit, filed 26 October 2026
“In addition, our co-founders have each pledged to dedicate 80% of their personal equity in Anthropic to philanthropic causes.”
Three Implications
FOR IPO BUYERS The S-1 says Class A holders’ voting power is limited to 49.9% because the Class F share carries a fixed 50.1%, and the IPO price range is blank.
FOR STRATEGIC PARTNERS The S-1 describes Class N holders as “primarily strategic business partners”, and says Class N converts to Class A on a sale or transfer to an unaffiliated third party.
FOR THE BENEFIT FUND The S-1 says the board may issue the fund up to an additional 2% of then-outstanding shares each time the share price rises 50% above the prior milestone, starting from the IPO price.
The framework sets out its question: “How the money flows, where it cracks, what it buys, who can absorb it, and what happens when revenue can’t catch up.”
As we read it, the ownership disclosures show the “who can absorb it” part from the equity side: cloud partners hold non-voting stakes above five percent, while a company-owned fund holds 5%. The framework was published in May 2026 and does not discuss this filing.
What Is Not Established
In the passages we read, the S-1 does not give Amazon’s or Google’s share counts, any co-founder’s or other individual holder’s percentage of the company, or the IPO price range. We put no dollar value on any stake. Altimeter’s and Commonwealth Bank’s positions are as reported by CNBC and Bloomberg, not as stated in the S-1.
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Anthropic’s S-1 puts 846,840,960 shares, 5% of its fully diluted count, in a public benefit fund it owns: 3.5 times the largest co-founder stake, by our arithmetic. The S-1 says Amazon and Google will each hold more than 5% after its preferred stock and notes convert, in non-voting stock outside the voting table.
A note on sourcing. The S-1 figures are from Anthropic, PBC’s Form S-1 filed with the SEC on 26 October 2026 (Our Commitment to Public Benefit, Principal and Selling Stockholders and Risk Factors), read on EDGAR on 27 October 2026. The 1.4% figure and the Commonwealth Bank report are Bloomberg’s; the Altimeter line is a CNBC segment title. The fully diluted base, the percentages and 3.5x are our arithmetic. Earlier reports are as covered in our pieces linked above. This is not investment advice. We did not contact Anthropic.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
