The revised S1 filing puts total commitments at $895bn, up from the more than $800bn reported the previous week. Roughly $320bn of that covers existing contractual obligations, while $451bn relates to signed leases yet to commence, expected to begin between 2026 and 2028, some subject to termination rights or other conditions. The Register's tally, including blank-check arrangements Anthropic values at $150bn to $175bn, puts the total compute tab north of $1 trillion.

Much of that spending is locked in. Deals with Microsoft, Google, Amazon and Broadcom total $437bn and are non-cancellable, with some requiring payment whether or not Anthropic uses the capacity. Only about $213bn of the $895bn in contracts allows it to avoid payments. The filing expects nearly $70bn in contractual obligations to be paid by September 2027 and roughly $447.5bn incurred by the end of 2030.

There are early signs the growth engine may be cooling. Revenue grew nearly 2.5 times between Q1 and Q2 this year, but the near-$17bn Q3 figure was up just 46 per cent on Q2, while compute and infrastructure costs grew 77 per cent over the same period. The prospectus itself warns that revenue growth at comparable rates is not expected and may not continue at all.

The filing also highlights a distribution risk: cloud marketplaces accounted for roughly 44 per cent of revenue in the nine months to September 30, and Anthropic's biggest compute providers, including Amazon, Google and Microsoft, all sell access to rival models. The IPO, which the New York Times reports could raise around $100bn, with up to $3.5bn expected from Japanese investors, will test whether markets buy the bet that enough compute turns this into a sustainable business.