Musk said Anthropic could never win — now he's its $120.5 billion landlord

Anthropic's IPO filing commits it to pay up to $120.5 billion to SpaceX's AI arm through 2029 — about $3.1 billion a month once all the computing capacity is delivered, which Anthropic expects in December. The money buys Nvidia-powered capacity from the company formerly known as xAI, which runs a rival AI lab of its own.

It is the second-biggest compute commitment in the filing, behind only the roughly $400 billion Anthropic lined up around Google's chips. And it is unusually loose: after early 2027 either side can walk away on 90 days' notice, while Anthropic's Google, Amazon and Microsoft deals mostly require payment whether the capacity is used or not.

The landlord is also the plaintiff: Musk is suing OpenAI for abandoning its nonprofit mission, while his own company collects billions from the lab that now leads the field.