Who owns Anthropic? What its IPO filing shows about the founders, Amazon, and Google

Anthropic is owned by its seven co-founders, its employees, hundreds of outside investors, and a group of strategic partners led by Amazon (AMZN) and Google, according to the S-1 it filed publicly on October 26, 2026. Control sits with a much smaller group. After the IPO, a single share held by the co-founders' LLC will carry 50.1% of shareholder votes, and the company's Long-Term Benefit Trust will elect a majority of the board.

Most of the percentage columns in the filing's ownership table are blank. Figures like those usually arrive in an amended filing, along with the price range and share count. The S-1 does list the co-founders' share counts and the terms of each Amazon and Google investment.

Anthropic's cap table so far

Some stakes below come straight from the S-1. The rest are our calculations, explained in the note at the end of this article.

The co-founders control the vote through one share

Anthropic will have five classes of common stock after the IPO, and only some of them vote. Class A, the stock the public will buy, carries one vote per share. Together, Class A holders get 49.9% of shareholder voting power, because the single Class F share is entitled to a fixed 50.1%.

That Class F share will belong to the Founder LLC. It votes as the continuing co-founders decide, with one vote each. It's set to end after a transition period that begins once fewer than three continuing co-founders have remained in the LLC for 90 days in a row. A supermajority of the continuing co-founders can also agree to redeem it sooner.

The Long-Term Benefit Trust holds the one Class T share. It elects the Class T directors, who will make up a majority of the board, and generally doesn't vote on other matters.

Class N stock has no vote except where the law requires one. "The holders of our Class N common stock are primarily strategic business partners," the S-1 says. Class N shares become Class A when they're sold to an unaffiliated buyer. Class E is a class Anthropic will authorize at the IPO for employees other than the co-founders. It votes only on certain limited matters and carries no economic rights.

Each co-founder beneficially owned between about 232 million and 244 million Class A shares as of September 30. Those counts include stock options and restricted stock units, or RSUs, that vest within 60 days.

*Our calculations. See the note at the end.

Daniela Amodei's count includes options and RSUs held by Holden Karnofsky, Daniela Amodei's spouse. Dario Amodei can also vote 4,621,120 shares held by two donor-advised funds under proxy agreements, which aren't counted in the table above.

Brown, Clark, Kaplan, McCandlish, and Olah are listed among the selling stockholders in the IPO, and the number of shares each will sell is blank. Each co-founder has also pledged to dedicate 80% of their personal Anthropic equity to philanthropic causes, according to the filing.

Amazon holds about 1.64 billion shares, with more in notes

Amazon began with convertible notes, which are loans that can turn into stock. The note purchases listed in the S-1 add up to $8.0 billion in cash from September 2023 through November 2025. Some of those notes converted into nonvoting preferred stock in the 2025 and early 2026 funding rounds.

Amazon then bought stock directly. It paid about $5.0 billion for Series G preferred shares in April 2026 and put $5.0 billion into the Series H round in May.

The preferred shares the S-1 attributes to Amazon convert into about 1.64 billion common shares, by our calculations, at 10 common shares each. That's close to 10% of Anthropic's fully diluted stock, using a share count that assumes all of Amazon's notes convert. The 12% cap described below could stop some of them from converting. Without those notes in the count, the same shares come to about 11%, by our calculations.

Amazon also holds $6.2 billion of notes that haven't converted. The notes carry fixed conversion prices of $2.0928 and $5.0478 a share, set in the 2023 and 2024 note agreements, well below what investors paid in Anthropic's 2026 funding rounds. At those prices, the notes would turn into about 1.84 billion more Class N shares. A note won't convert if Amazon would then hold more than 12% of Anthropic's capitalization, as the notes define it, unless Amazon waives that limit. Any blocked portion becomes a non-interest-bearing "rollover note" that tries to convert again at the end of each quarter after the IPO.

Amazon values the two holdings differently in its quarterly filing. It carried the nonvoting preferred stock at about $92.5 billion as of June 30, 2026. That figure starts from the stock's value when Amazon bought it or converted notes into it, then is adjusted for observable changes in its price. Amazon recorded about $50.5 billion of those upward adjustments in the second quarter.

The notes that hadn't converted had an estimated fair value of about $97.9 billion on the same date, including about $92.0 billion of unrealized gains. Amazon estimates that value using the notes' terms, Anthropic's other securities, new securities offerings, and a discount because the notes can't easily be sold.

Under an April 2026 agreement, Amazon can still provide up to $15.0 billion more in stock or notes. The money becomes available in $5.0 billion steps tied to computing-capacity milestones.

Google's new shares are capped at 14.99%

The S-1 traces these investments to Google:

• $2.0 billion of notes issued in three pieces from September 2023 to September 2025, all since converted into nonvoting preferred stock
• About $1.3 billion more in a note from August 2024, converted in 2025
• About $10.0 billion for 38.6 million Series G preferred shares in March 2026
• $10.0 billion in the Series H round in May 2026

Those shares come to at least 1.11 billion on a converted basis, by our calculations. The filing doesn't attribute any stock Google may have bought before its 2023 notes. As of March 2025, Google owned 14% of Anthropic, according to court documents seen by The New York Times and reported by DatacenterDynamics.

Google has $20.0 billion of financing left under its March 2026 agreement. Shares issued under that agreement stop at the point where Google would own more than 14.99% of Anthropic on a post-money, converted basis, unless Google waives the limit. Any excess becomes a rollover note.

Anthropic also gave Google an option to buy up to $10.0 billion of Class N stock at the IPO price, in a private sale alongside the offering. Exercising it would cut the $20.0 billion left under the 2026 agreement by the same amount.

Microsoft and hundreds of other investors also own stakes

"Amazon, Google, and Microsoft, through their respective affiliates, have made significant equity investments in our company," the S-1 says. It gives no amount or share count for Microsoft.

Microsoft committed up to $5 billion and Nvidia (NVDA) up to $10 billion when the three companies announced their partnership on November 18, 2025. The S-1 describes a "strategic partnership" with Nvidia covering chips and engineering work, and it doesn't break out any Anthropic shares held by Nvidia. In September, Nvidia was in talks to anchor the IPO with up to $10 billion, Reuters reported.

Anthropic sold $21.7 billion of nonvoting Series G-2 stock to five investors from January to May 2026. Google's $10.0 billion and Amazon's $5.0 billion account for $15.0 billion of it. The S-1 doesn't say who bought the other 26.0 million shares, sold for about $6.7 billion in January and February.

Advanced Micro Devices (AMD) committed in July 2026 to buy up to $5.0 billion of Class N stock. Anthropic can draw that money in steps as AMD delivers and deploys its GPUs, and it expects the first step in 2027.

Broadcom (AVGO) could end up with stock through a $42.0 billion note facility that Anthropic can draw only to pay rent on leased equipment. The holder can convert those notes into Class N stock at 90% of its 30-day volume-weighted average price, or 85% if Anthropic is missing certain revenue conditions. None of those notes had been issued as of June 30.

The S-1 lists 305 buyers for the Series H-1 shares alone.

Source: Anthropic's S-1. Each preferred share converts into about 10 common shares.

The $65 billion Series H set a $965 billion post-money valuation. Altimeter Capital, Dragoneer, Greenoaks, and Sequoia Capital led the round. Anthropic also named Micron, Samsung, and SK hynix as strategic infrastructure partners in it.

Spark Capital is the only venture fund named in the S-1's related-party section, because Spark's Yasmin Razavi sits on Anthropic's board. Spark funds put about $777 million into six rounds, from Series C in 2023 through Series H.

In an April 2026 tender offer, a group of outside buyers paid $25.9136 a share for 179.9 million Class A shares, or $4.66 billion. The sellers included current and former employees, other service providers, and donor-advised funds. Dario Amodei, Daniela Amodei, and Chief Financial Officer Krishna Rao were among them.

Anthropic gave 846,840,960 Class N shares to the Anthropic Public Benefit Fund, a wholly owned subsidiary. Its initial managers are Dario Amodei, Daniela Amodei, Jack Clark, and Neil "Buddy" Shah. The board may add up to 2% more each time the stock price rises 50% above its last milestone, starting from the IPO price.

In October 2025, Anthropic bought back 4,453,900 Series B shares from the US government, which had received them as forfeitures in legal proceedings involving former holders. Anthropic resold them at the same time, at the same price, to nine investors for about $627 million.

Just before the IPO, all preferred stock converts into Class A or Class N common stock. Amazon's notes are expected to convert into Class N up to its cap, with the rest staying outstanding as rollover notes. The final split depends on the size of the offering and whether Amazon waives the cap. Anthropic's S-1 also shows an $80.7 billion first-half net loss, most of it from revaluing those notes and similar instruments.

The co-founders and certain holders of more than 0.5% of fully diluted shares agreed to lock-ups that can run until shortly after Anthropic reports results for the quarter ending September 30, 2027.

How we calculated the estimates: Anthropic says its 846,840,960-share grant to the Anthropic Public Benefit Fund equals 5% of its fully diluted shares as of June 30, 2026, assuming full conversion of Amazon's notes. That implies about 16.9 billion fully diluted shares, which we used as the denominator. The co-founders' counts are as of September 30 and include options and RSUs vesting within 60 days. Amazon's and Google's counts add the preferred shares the S-1 ties to each company, converted at 10 common shares per preferred share. The dates of the inputs don't line up exactly, so the estimates are approximate until the amended filing.