Anthropic's IPO: VCs will make billions, but Amazon stands to make far more

Anthropic's public listing will deliver big gains to many investors. Stakes held by Menlo Ventures, Sequoia, Sound Ventures, Spark Capital and others are expected to return billions of dollars.

Yet according to the S-1, none of these firms owns 5% of the company. That is the threshold for appearing in the principal stockholders' table. This is unusual for a tech IPO, where lead venture investors typically hold double-digit stakes in the startups they backed. The reason is Anthropic's sheer size. At a $965 billion private valuation, a single percent is worth nearly $10 billion. According to recent Bloomberg figures, Menlo's roughly $14 billion position amounts to only about 1.5% of the company.

Anthropic did, however, sell large stakes to strategic partners, the companies it also does business with. Amazon is likely to be the single largest financial beneficiary of the IPO.

Notes that turned into shares

Amazon first backed Anthropic in 2023, committing up to $4 billion, and has invested billions more since. Rather than buying stock outright, it structured much of that money as convertible notes. These are debt instruments that convert into shares upon an IPO or sale of the company.

Per the S-1, Amazon held convertible notes with $6.2 billion in outstanding principal as of June 30. That is Anthropic's entire debt load. But as the company's valuation climbed from round to round, the shares those notes convert into grew far more valuable. Amazon's own filings valued the holdings at $97.9 billion as of June 30.

Anthropic had to record the rising value of these obligations on its books. The adjustments appear on its income statement under "change in fair value of convertible notes, derivative liabilities, and SAFEs." That line totaled $72.4 billion for the first half of 2026. The charge is non-cash: no money actually left the company.

The S-1 says Amazon's notes could convert into as many as 1.84 billion shares. However, a cap limits Amazon to 12% of Anthropic's "partially diluted" share count, which includes some shares not yet issued, such as stock options. Amazon can waive the cap. Notes that cannot convert right away remain outstanding and convert in later quarters under the same limit.

Equity and the cloud

The notes are not Amazon's only holding. According to its quarterly report, Amazon put another $10 billion into nonvoting preferred stock in the second quarter, investing $5 billion in each of Anthropic's last two rounds. Combined with the $8 billion it invested in notes from 2023 through 2025, that brings Amazon's total investment to about $18 billion. Anthropic has also committed to spend at least $110 billion on AWS over the next ten years.

Google is set for a major windfall too. Court filings reported by The New York Times show it held about 14% of Anthropic early last year. It has invested more since, including $10 billion in April. Later large rounds likely diluted that stake, and PitchBook analyst Harrison Rolfes estimates it is now closer to 5.6%. Anthropic has also committed at least $114 billion in cloud spending to Google through 2033.

VCs have little reason to complain. But the S-1 makes clear that the biggest winners of the IPO may be tech giants like Amazon, which backed a would-be rival early and now sells it much of the computing power it runs on. The filing itself warns that some of these cloud providers build competing AI models and may not always want the same things Anthropic does.

Source: TechCrunch