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

Why it matters

Anthropic's IPO filing reveals an unusual ownership picture: none of its major venture backers—Menlo Ventures, Sequoia, Sound Ventures, or Spark Capital—reaches the principal stockholders threshold, because Anthropic's enormous private valuation makes even multibillion-dollar positions small fractions of the company. The bigger winners are strategic partners. Amazon structured much of its backing as convertible notes, which now convert into far more valuable shares, and it also bought nonvoting preferred stock across recent funding rounds. Anthropic must record the rising value of what it owes as a non-cash accounting charge. Amazon's conversion is capped at a share of the partially diluted count, with excess notes converting later. Anthropic has also committed to heavy spending on AWS, and Google holds a substantial stake plus its own cloud commitments. The filing warns that some cloud providers building rival AI models may have interests that diverge from Anthropic's, highlighting the tension between investors and competitors.