VCs will make billions on Anthropic’s IPO, but Amazon is set to make much (much) more

Anthropic's S-1 reveals an unusual cap table. Big venture backers like Menlo Ventures, Sequoia, Sound Ventures, and Spark Capital stand to make billions, yet none crosses the 5% line to appear among principal stockholders. At a $965 billion private valuation, even a multibillion-dollar stake is a sliver.

The heavyweight is Amazon. It holds convertible notes with $6.2 billion in principal outstanding, which Amazon's own filings valued at $97.9 billion as of June 30, plus $10 billion in nonvoting preferred stock. Anthropic has also committed to spend at least $110 billion on AWS over ten years. Google, with its own stake and at least $114 billion in cloud commitments, is in a similar spot. This is the shape of power in frontier AI, now on paper.

I keep coming back to one line in this story: the S-1 itself warns that some of Anthropic's cloud providers build rival models and may not always want what Anthropic wants. That is the company telling public investors, in legal language, that its biggest backers are also its landlords and its competitors.

We think that is the most important fact in the filing. Frontier AI is so compute-hungry that the labs cannot exist without hyperscalers, and the hyperscalers have structured their bets to win in three ways at once: equity upside, cloud revenue, and strategic leverage over a competitor. Amazon's convertible notes are a good example. It put in money as debt that converts at IPO, so as Anthropic's valuation soared, Amazon's claim grew with it. Anthropic, in turn, booked a $72.4 billion non-cash charge for the first half of 2026 to reflect that rising liability. No cash left the building, but the accounting tells you how much of the company's success is already spoken for.

There are guardrails. A cap limits Amazon to 12% of Anthropic's partially diluted share count, though Amazon can waive it, and unconverted notes roll forward under the same limit. That waiver option is worth watching; a cap the holder can lift is a soft cap.

For the venture industry, this is a strange victory lap. Firms will book enormous gains while holding small percentages, which tells you how far the AI capital game has moved past classic VC math. For the public, the question is concentration. If the companies selling compute also own large pieces of the labs buying it, competition in AI starts to look like a negotiation among a few giants. We are glad Anthropic is going public and disclosing all this. Sunlight is good. But we would not mistake an IPO for independence.

Amazon first committed up to $4 billion to Anthropic in 2023, investing about $8 billion in notes from 2023 through 2025 and another $5 billion in each of Anthropic's last two funding rounds, for roughly $18 billion in total. Google held about 14% as of early last year according to court filings reported by The New York Times; a PitchBook analyst estimates its current stake is closer to 5.6% after dilution. Google also invested $10 billion in April.