The venture capitalists get billions from the Amazon Anthropic IPO. But the filing’s main character is Amazon.
When Anthropic filed to go public, the numbers behind the Amazon Anthropic IPO told a familiar story at first glance: the venture capitalists who backed the AI lab early are about to make billions. Menlo Ventures and the other venture firms hold stakes worth billions.
But the filing tells a second story, and it is the stranger one. No venture firm owns even 5% of Anthropic. The filing’s main character isn’t a venture firm at all. It is Amazon — and Amazon isn’t playing one role in this story. It is playing three.
The creditor
Start with the debt. Amazon structured much of its early backing as convertible notes — loans that turn into shares when the company goes public or gets sold. According to the S-1, Amazon holds $6.2 billion of those notes. That is not a slice of Anthropic’s debt. It is all of it.
Amazon first committed to invest up to $4 billion in Anthropic in 2023, then poured billions more in through the notes. As Anthropic’s valuation soared across successive funding rounds, the notes became far more valuable — Amazon’s own filings put their value at $97.9 billion as of June 30, 2026.
And here is the accounting twist. Because the notes are worth so much more than Anthropic borrowed, the company had to record the growing value of what it owes on its own books. In the first half of 2026, that line on the income statement — “change in fair value of convertible notes, derivative liabilities, and SAFEs” — totalled $72.4 billion. It is a non-cash charge; no money left the company. But it means Anthropic’s own success made its books look $72.4 billion worse — driven by the rising value of the notes it owes Amazon.
The investor
The notes are only part of it. In the second quarter of 2026, Amazon put another $10 billion into nonvoting preferred stock — $5 billion in each of Anthropic’s last two funding rounds, according to Amazon’s quarterly report for the period ended June 30. Add the $8 billion of notes from 2023 through 2025, and Amazon’s total investment comes to about $18 billion.
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. But Amazon can waive the cap. Notes that cannot convert stay outstanding and convert in later quarters, under the same limit. The ceiling on Amazon’s ownership, in other words, is a ceiling Amazon itself can lift.
The cloud supplier
Then there is the third role, and it is the one that keeps paying. Beyond any stock gains, Anthropic has committed to spend at least $110 billion on Amazon Web Services over the next ten years. Google has secured at least $114.5 billion in cloud commitments from Anthropic through 2033, and Microsoft at least $44.9 billion. All told, that is $269.4 billion in cloud spending promised to the three companies.
These are not handshake deals: the filing makes them non-cancellable unless the provider breaks the contract, and under the Google and Amazon deals Anthropic pays the difference if it uses less than it promised. Anthropic’s revenue for the first half of 2026 was $16.3 billion. Its long-term purchase commitments stood at about $265.6 billion by June 30 — most of it cloud hosting — plus $321.4 billion in leases that had not yet started.
Anthropic rents its future by the decade, and the rent is owed to the same companies that own pieces of it.
The venture capitalists, meanwhile
Set against that, the venture story looks almost quaint. In a typical tech IPO, lead venture investors hold double-digit-percentage stakes in the startups they backed, as TechCrunch noted. At Anthropic’s $965 billion private valuation, a single percentage point is worth nearly $10 billion — so Menlo’s roughly $14 billion position amounts to about 1.5% of the company. The venture firms will be rich. They just won’t be the main characters of this IPO.
The tension the filing flags itself
Here is the part the S-1 warns about in its own pages. Anthropic’s cloud providers also build rival AI models, and the filing says they “may not always want the same things that Anthropic does.” The providers have visibility into Anthropic’s pricing and commercial terms, and could favour their own models over Claude.
The dependence runs both ways and neither way is comfortable. Anthropic relies on Amazon’s data centres and chips to train Claude, while Amazon distributes Claude through its Bedrock platform. Google sells Claude through its cloud platform while building rival models of its own. The companies Anthropic depends on for its existence are also its competitors — and, in Amazon’s case, its creditor and one of its largest investors.
What Amazon is not
None of this makes Amazon Anthropic’s owner. There are limits on its position, but they are conditional: the 12% conversion cap is waivable, the preferred stock is nonvoting, and the governance rights attached to any of it are questions the reporting so far leaves unanswered. And the venture firms, for all the talk of their small percentages, still made billions — nobody at Menlo is complaining about a $14 billion position.
The point is not that Amazon controls Anthropic. The point is that one company sits on every side of the table at once. It financed the rise. It holds the debt. It sells the computing power. The IPO can convert the debt into equity. The cloud contracts keep paying for a decade. And the question the filing leaves open is the one worth asking: once the gains are actually measured — not the exposure, but the money — who gains most?
