Anthropic's SpaceX bill hits $3.1B a month. It can walk away.

Anthropic expects to pay SpaceX's AI unit about $3.1B a month once all contracted capacity is delivered in December, or roughly $37B a year. That's about $9.3B a quarter, far more than the $5.56B Anthropic spent on all compute and infrastructure in Q2.

The $120.5B through 2029 is a ceiling, not a locked-in bill. The initial non-cancelable periods end in January and March 2027, and after that either side can leave on 90 days' notice. Google (at least $114.5B through 2033) and Amazon (at least $110B through 2036) look smaller on paper, but those are floors, and Anthropic can generally exit them only if the supplier commits an uncured material breach. Broadcom's roughly $161B in TPU leases is the largest named commitment.

The revenue comparison depends on the quarter. $3.1B is about 80% of Anthropic's average monthly revenue in Q2 ($11.6B for the quarter), but only around 55% if Q3 came in near the reported $16.8B, a figure that isn't in the S-1. Margins are the bigger worry: Q2 GAAP operating margin was 8%, and the filing warns it "may compress" as large blocks of compute come online. Anthropic also expects to lean more on pricier short-term capacity in the near term.

Why it matters: Anthropic is paying a premium for compute now and keeping an exit, a bet that demand keeps outrunning its long-term supply.