Anthropic’s filing to go public shows that Amazon could be the single largest financial winner from the AI company’s IPO. Venture capital firms are also set to earn billions, but their stakes are small by percentage.
The details come from Anthropic’s S-1, the document a company files before listing its shares. They were reported by TechCrunch on October 27.
Venture Firms Hold Small Slices
Firms including Menlo Ventures, Sequoia, Sound Ventures, and Spark Capital backed Anthropic. Their stakes are expected to return billions of dollars.
Still, none of these firms owns 5% of the company. That is the threshold for appearing in the S-1’s principal stockholders table.
In a typical tech IPO, lead venture investors often hold double-digit stakes. Anthropic’s size explains the difference. At its $965 billion private valuation, a 1% stake is worth nearly $10 billion.
Menlo’s position, for example, is worth about $14 billion, according to figures reported by Bloomberg. That equals only about 1.5% of the company.
How Amazon’s Stake Grew
Amazon first backed Anthropic in 2023 with a pledge to invest up to $4 billion. It has added billions more since then.
Much of that money came as convertible notes. These are a type of debt that turns into shares when a company goes public or is sold.
The S-1 shows Amazon held notes with $6.2 billion in principal outstanding as of June 30. That amount is Anthropic’s entire debt load.
As Anthropic’s valuation rose, the shares behind those notes became worth far more. Amazon’s own filings valued the notes at $97.9 billion as of June 30.
Anthropic had to record that rising value on its books. A line tied to the change in fair value of its notes and similar instruments totaled $72.4 billion for the first half of 2026. The charge is non-cash, so no money left the company.
The notes could convert into as many as 1.84 billion shares. A cap limits Amazon to 12% of Anthropic’s partially diluted share count, though Amazon can waive it. Notes that cannot convert will stay outstanding and convert later under the same limit.
Amazon also invested $10 billion in nonvoting preferred stock in the second quarter. It put $5 billion into each of Anthropic’s last two funding rounds.
Together with $8 billion in notes from 2023 through 2025, Amazon’s total investment comes to about $18 billion. Anthropic has also committed to spend at least $110 billion on Amazon Web Services over the next 10 years.
Google is also in line for large gains. It held about 14% of Anthropic as of early last year, according to court filings reported by The New York Times, and invested another $10 billion in April.
PitchBook analyst Harrison Rolfes estimates Google’s current stake is closer to 5.6% after later funding rounds. Google has also secured at least $114 billion in cloud commitments from Anthropic through 2033.
The S-1 includes a warning about these partners. It states that some cloud providers also build rival AI models and may not always want the same things Anthropic does.
