Anthropic expects to pay SpaceX’s AI unit approximately $3.1 billion a month for computing capacity once all of it has been delivered, which it expects in December 2026, according to the amended Form S-1 it filed with the SEC on Monday, 2 November. SpaceX’s own IPO filing had described Anthropic agreeing to pay $1.25 billion a month, so the expected monthly fee is about 2.5 times that figure, by our arithmetic.
The filing puts the total at up to $120.5 billion over terms extending into 2029. It also says either side may cancel each agreement on 90 days’ notice once initial non-cancelable periods end in January and March 2027.
Stated amount per compute arrangement in Anthropic’s Form S-1/A, in billions of dollars: minimum spend (Google, Amazon, Microsoft), up-to amounts (SpaceX AI, Nscale), as-delivered (Lambda), equipment-lease rent excluding interest (Broadcom) and the expected AMD spend. Categories differ and are not added up. Source: Anthropic PBC, Form S-1/A, 2 Nov 2026. Chart: FourWeekMBA.
The key insight: Anthropic’s amended S-1 says it expects to pay SpaceX’s AI unit about $3.1 billion a month once all capacity arrives in December 2026, up to $120.5 billion into 2029, and that either side may cancel each agreement on 90 days’ notice from early 2027.
The S-1/A says that between May and October 2026 Anthropic entered into and amended several agreements with SpaceXAI, formerly X.AI LLC, a wholly owned subsidiary of Space Exploration Technologies Corp., to access compute powered by Nvidia GPUs.
Under those agreements, it says, Anthropic “agreed to spend an aggregate of up to $120.5 billion over terms extending into 2029, consisting of approximately $3.1 billion in the aggregate per month once all capacity has been delivered, which we expect in December 2026, with different fees during capacity ramping periods”.
It adds that after the initial periods, “each agreement may be cancelled by either party upon 90 days’ advance written notice”.
Monthly fee for SpaceX AI compute as described in SpaceX’s amended S-1 (May 2026 agreements, $1.25 billion a month) and in Anthropic’s 2 November S-1/A (approximately $3.1 billion a month once all capacity is delivered, expected December 2026). Sources: Anthropic PBC Form S-1/A; Space Exploration Technologies Corp. amended Form S-1.
From $1.25 Billion to $3.1 Billion a Month
SpaceX’s amended S-1 said Anthropic “has agreed to pay us $1.25 billion per month through May 2029, with capacity ramping in May and June 2026 at a reduced fee”, as we noted in our check of the reported $45 billion Anthropic deal. Anthropic’s filing says the agreements were amended through October.
At $3.1 billion a month, a full quarter would come to about $9.3 billion, by our arithmetic. SpaceX’s third-quarter 10-Q shows one AI customer accounting for 34.5% of its $14,575 million revenue, about $5.03 billion by our arithmetic, which Bloomberg reported was Anthropic. The SpaceX filing does not name the customer.
On Anthropic’s side, $3.1 billion a month is about $37.2 billion a year, or roughly 55% of its third-quarter revenue of $16,956 million multiplied by four, by our arithmetic.
The Exit Clause Sets SpaceX Apart
Of the compute agreements the S-1/A describes in detail, the SpaceXAI ones are the only ones it says either party may cancel on short notice. It describes its Google, Amazon and Microsoft agreements as minimum commitments payable “regardless of actual usage”.
It says its Nscale and Lambda agreements can end only in limited circumstances, such as delivery failures, and that its equipment leases with Broadcom and its financing partners are non-cancelable by either party during the lease period except by the lessor in the case of a default.
It says Anthropic agreed to spend up to approximately $44.6 billion with Nscale over terms extending into 2033, and approximately $41.3 billion with Lambda over terms extending into 2034, in both cases “with fees accruing only as capacity is delivered to and accepted by us”.
Its five-year master equipment leases with Broadcom and financing entities carry rent “equal to an aggregate of approximately $161.2 billion excluding interest”, for TPU-based capacity.
For AMD, the filing says the agreement “does not specify a fixed dollar commitment”, but that if Anthropic procures the full initial capacity of AMD-based Helios systems, “we expect aggregate expenditures to exceed $20.0 billion over the term of the agreement”. AMD has committed to buy up to $5.0 billion of Anthropic’s Class N common stock in increments tied to GPU delivery milestones, the filing says. We reported the $5 billion AMD and Anthropic deal in July.
Arrangements without a fixed dollar commitment are left out of its contractual obligations table, and Anthropic estimates payments under them at “approximately $150 billion to $175 billion”.
As we read the filing, the SpaceX agreements are the flexible end of Anthropic’s compute map: the filing describes the Google, Amazon and Microsoft agreements as minimums payable regardless of usage and the Broadcom leases as non-cancelable, while the SpaceX ones can be cancelled by either party on 90 days’ notice after their initial periods.
As we read the two IPO filings together, the expected monthly fee is about 2.5 times the $1.25 billion SpaceX described, after amendments the S-1/A dates between May and October 2026.
Anthropic’s amended Form S-1
“each agreement may be cancelled by either party upon 90 days’ advance written notice”
Three Implications
FOR SPACEX INVESTORS SpaceX’s third-quarter 10-Q shows one AI customer at 34.5% of revenue, which Bloomberg reported was Anthropic; the S-1/A puts the expected monthly fee at about $3.1 billion and lets either side cancel on 90 days’ notice from early 2027.
FOR IPO INVESTORS The S-1/A says $3.1 billion a month applies once all capacity has been delivered, which Anthropic expects in December 2026, with different fees during ramping periods.
FOR OTHER COMPUTE SUPPLIERS The filing lists Nscale at up to approximately $44.6 billion and Lambda at approximately $41.3 billion, with fees accruing only as capacity is delivered and accepted.
The framework says: “The $1T capex cycle is being underwritten by a $1T concentrated demand commitment from two counterparties whose combined free cash flow is deeply negative.”
As we read it, Anthropic’s filing shows one of those counterparties spreading its compute across Google, Amazon, Microsoft, SpaceX, Broadcom, Nscale, Lambda and AMD on different terms. The framework is the owner’s argument and does not discuss this filing.
Short explainer: what concentration means when one customer or one supplier carries a large share of the business. Video: FourWeekMBA.
What Is Not Established
The filing does not say why the expected monthly fee rose from the $1.25 billion in SpaceX’s filing, whether the additional capacity sits in the same data centres, or how much Anthropic will pay during the ramping periods before December. It does not say whether either side expects to use the 90-day cancellation right. That Anthropic is the SpaceX customer behind 34.5% of revenue is Bloomberg’s report, not a statement in either filing. The 2.5-times, $5.03 billion, $9.3 billion, $37.2 billion and 55% figures are our arithmetic.
This Week In The AI Supercycle
Anthropic’s Reality Check, The Capital Squeeze, & The New World Order
This week’s issue: for two years the AI build-out was priced as a growthstory. This week it started being priced as a credit story.
Anthropic’s amended S-1 says it expects to pay SpaceX’s AI unit about $3.1 billion a month from December 2026 under agreements worth up to $120.5 billion into 2029, about 2.5 times the monthly fee SpaceX’s own filing described. Unlike the other compute agreements the filing details, each SpaceX agreement can be cancelled by either party on 90 days’ notice once its initial period ends in early 2027.
A note on sourcing. Anthropic figures and quotations are from its Form S-1/A filed with the SEC on 2 November 2026; SpaceX’s $1.25 billion monthly fee is from its amended S-1 and its third-quarter customer share from its 10-Q, as quoted in our earlier pieces; Anthropic’s identification as that customer is Bloomberg’s report. The 2.5-times, $5.03 billion, $9.3 billion, $37.2 billion and 55% figures are our arithmetic.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
