How rich will Anthropic's seven founders become after the company goes public?

Anthropic's stock market debut promises to be not only one of the largest IPOs in tech history, but also an event that will make the company's seven co-founders multibillionaires. According to its updated S-1 registration statement, at the midpoint offering price of $74, their stakes would be worth approximately $17.8 billion to $18.1 billion each. The largest stake belongs not to CEO Dario Amodei, but to Tom Brown, the head of computing who is less well known outside the company.

Anthropic is preparing to offer investors shares priced between $70 and $78. Even after selling some shares in the IPO, the founders will retain almost all of their enormous holdings. But their wealth is only part of the story: they also intend to retain decisive control over shareholder voting and have pledged to devote a significant portion of their personal stakes to charity.

Tom Brown Emerges as the Wealthiest Co-Founder

According to Anthropic's filings, Tom Brown owns approximately 244 million shares in the company. At $74 per share, his stake is valued at approximately $18.1 billion. He plans to sell 3.38 million shares in the IPO, worth roughly $250 million. After the transaction, he will retain a stake worth about $17.8 billion.

Brown serves as Chief Compute Officer and leads the technical organization responsible for securing, scaling, and efficiently using Anthropic's computing resources. He founded the company in January 2021 alongside Dario and Daniela Amodei and four other colleagues.

His contribution to the development of modern language models began long before Anthropic was established. Before joining the new company, Brown worked at OpenAI, where, according to the S-1 filing, he led engineering development for GPT-3. Together with Dario Amodei, he also helped develop an approach that Anthropic calls deep RLHF. This technology helped turn base large language models into conversational assistants like Claude.

The other six founders trail Brown only slightly. According to the S-1, their holdings range from approximately 232 million to 243.4 million shares. At the midpoint offering price, each would hold a stake worth about $17.9–18 billion before accounting for planned sales.

Dario Amodei, Anthropic's CEO, also controls the voting rights of an additional 4.6 million shares through proxies. However, his personal shareholding is smaller than that of every other founder.

The Seven Founders Will Retain Control of the Company

Such large founder stakes are not unusual in Silicon Valley. For example, ahead of Snap's 2017 IPO, Evan Spiegel and Bobby Murphy retained shares with enhanced voting rights, allowing them to control approximately 89% of the voting power after the offering.

What sets Anthropic apart is not just that it has seven founders with multibillion-dollar stakes, but also how evenly ownership is distributed among them. However, their equity holdings are not their only source of influence.

Immediately before the IPO, Anthropic intends to issue a special Class F share to an LLC controlled by the seven co-founders. Although it is just one share, it will carry 50.1% of the total voting power on matters submitted to shareholders. This includes the election of directors, except those appointed by the Long-Term Benefit Trust, a special trust representing the company's long-term interests.

The founders will therefore be able to retain control over key corporate decisions even after going public and bringing in a large number of outside shareholders. This is an important consideration for investors: buying Anthropic shares will not mean gaining a proportional say in how the company is run.

This model also has an unusual charitable component. Each of the seven co-founders has pledged to devote 80% of their personal stake in Anthropic to charitable causes. The filing does not disclose all the details of how the funds will eventually be distributed, but the scale of the commitment is striking: at the company's current valuation, it potentially amounts to tens of billions of dollars per founder.

Amazon and Google Will Also Profit from the IPO

The founders are far from the only potential beneficiaries of the offering. Anthropic's largest shareholders will also include the technology giants that have supported the company with investments and infrastructure.

Following the conversion of Amazon's and Google's shares, each company will own more than 5% of Anthropic. At the midpoint offering price, Amazon's stake, comprising about 1.92 billion shares, would be worth approximately $142 billion. Google's stake is valued at approximately $132 billion.

This makes Anthropic's IPO an event with an enormous potential financial impact on two of the largest players in the cloud and AI markets. Both companies have invested in the developer while also pursuing their own strategic interests in artificial intelligence.

Venture capital investors that backed Anthropic at much earlier stages, when its valuation was nowhere near today's level, could also reap substantial profits.

Spark Capital stands out among them. The firm first invested in Anthropic in 2023, when the company was valued at $4.5 billion. Since then, Spark-affiliated entities have participated in at least six funding rounds. Its investments are disclosed in greater detail in the filings than those of many other firms, partly because Spark partner Yasmin Razavi sits on Anthropic's board of directors.

Menlo Ventures led a funding round in 2024, when Anthropic was valued at about $18 billion. The firm has invested more than $1.3 billion in the company in total and, according to a source familiar with the matter, acquired a stake of between 1.5% and 2%.

Lightspeed Venture Partners is considered Anthropic's largest venture capital shareholder, owning almost 2% of the company. It led a funding round in late 2024 at a valuation of $61.5 billion and continued to increase its investment.

A comparable stake of between 1.5% and 2% belongs to Iconiq, which has invested about $6 billion in Anthropic. Bessemer Venture Partners, which first invested in the company in its Series D round in 2024, also participated in every subsequent round. Its total investment reached about $800 million, and its stake approached 1%. This is the largest investment in the firm's history.

Other notable investors include Coatue, which invested $4.75 billion, and Sound Ventures, with investments exceeding $400 million. Major shareholders also include Altimeter, Dragoneer, Greenoaks, Sequoia Capital, Salesforce Ventures, Mubadala, and Founders Fund.

The IPO Will Reveal Who Has Profited from the AI Boom

Anthropic's offering is becoming a snapshot of the entire AI economy: on one side are seven founders who have retained nearly equal multibillion-dollar stakes and voting control; on the other are Amazon and Google, whose investments in the developer could turn into assets worth more than $100 billion, along with venture capital firms that backed the company at an early stage.

For now, however, the stated valuations remain estimates. The value of the stakes is based on the assumed IPO price, while the actual market price after trading begins could be higher or lower. Share sales by the founders also mean that their actual wealth after the offering will depend on how many shares they sell and how the share price changes.

But one thing is already clear: Anthropic's IPO will be more than just a way to raise tens of billions of dollars. It will show how the financial gains from the generative AI boom are distributed—and how far founders and early investors can go if the market continues to value technology companies in the trillions.