Anthropic's confidential IPO prospectus reveals up to $84.5B in SpaceX compute deals through 2029
Reuters' review of Anthropic's confidential IPO prospectus surfaces compute agreements with SpaceX worth up to $84.5 billion through 2029 — nearly double earlier disclosures — inside a $518 billion decade-long infrastructure buildout.
Anthropic's confidential IPO prospectus reveals compute agreements with SpaceX worth up to $84.5 billion through 2029 — nearly double the figure previously on record — according to reporting from Reuters and The Information on September 29, 2026.
The disclosure is one slice of a much bigger picture: the prospectus lays out at least $518 billion in planned infrastructure spending over the next decade, spread across six technology partners, with roughly 80 percent of it locked in as non-cancelable commitments or minimum payments that come due whether the capacity is fully used or not. Anthropic didn't respond to Reuters' request for comment.
The number that nearly doubled#
The new SpaceX figure is a big revision. SpaceX's own IPO paperwork had previously indicated an agreement worth nearly $45 billion — roughly $1.25 billion a month over about three years. The prospectus now lists agreements that could reach $84.5 billion through 2029, covering Nvidia-based hardware capacity accessed through SpaceX's infrastructure, according to The Information's Grace Kay via Techmeme.
One report identifies the facility as SpaceX's Colossus 1 data center, described as housing more than 220,000 Nvidia GPUs drawing over 300 megawatts of power, with Anthropic securing exclusive access in May 2026. Take the facility specifics with some caution — they come from secondary reporting — but the core number traces back to Reuters' review of the prospectus itself, which multiple outlets corroborated on Tuesday. SpaceX's SPCX shares reportedly rose about 3 percent on the day.
The unusual clause: a 90-day exit#
The striking part isn't just the size — it's the flexibility. Most of the SpaceX commitment can reportedly be terminated with 90 days' written notice, an unusually short leash for a deal measured in the tens of billions. That structure is the opposite of Anthropic's other infrastructure contracts, where the money is effectively committed regardless of usage.
The flexibility looks deliberate. One analysis of the arrangement notes that Anthropic has been using the Colossus capacity mainly for inference — serving surging user demand — rather than training new frontier models. Inference capacity is fungible and spiky; training capacity is planned years in advance. A cancelable contract buys optionality: rent the overflow now, scale it down if your own data centers or other partners catch up.
The $518 billion shopping list#
Zoom out and the SpaceX number is one line item in what the prospectus frames as the central investment thesis: at least $518 billion over a decade across six partners. Per reporting on the document, the commitments break down roughly as follows:
| Partner | Commitment | Terms (as reported) |
|---|---|---|
| ≥ $111.1 billion | Must-pay structure — Anthropic pays the difference if spending falls short | |
| Amazon | $110 billion | Similar must-pay terms |
| Broadcom | ~$161.2 billion | Equipment leases, largely non-cancelable |
| SpaceX / xAI | Up to $84.5 billion through 2029 | Mostly cancelable with 90 days' notice |
| Microsoft | $31.4 billion | Non-cancelable through May 2033, barring an uncured material breach |
| AMD | Over $20 billion | Expected computing capacity, per reporting |
Two things stand out in the table. First, the custom-silicon track is nearly as big as the GPU one: Broadcom-related equipment leases alone run to about $161 billion, with AMD capacity reportedly expected to exceed $20 billion. Second, the SpaceX deal is the only one that reads like a rental rather than a purchase — which may explain why it's the fastest-growing.
What to watch#
- The public filing. The prospectus is still confidential; a public S-1 would land at least 15 days before Anthropic starts marketing its shares to investors. Expect the audited version of these numbers there — and any revisions.
- Whether the 90-day option gets used. If Anthropic trims the SpaceX commitment once other capacity comes online, it signals confidence that its locked-in deals are enough. If it grows instead, demand is still outrunning every plan.
- The custom-silicon mix. Broadcom leases at $161 billion and AMD capacity north of $20 billion suggest Anthropic's future is not only Nvidia GPUs — the share of inference moving to custom chips is the subplot that matters for margins.
- The economics underneath. We covered the filing's headline numbers earlier: roughly $61 billion in revenue against a $42 billion net loss. The prospectus makes clear where the money goes — compute, at a scale where a single partner agreement exceeds the market cap of most public companies.
The full breakdown is drawn from AI Stock Wire's summary of the prospectus reporting and Crypto Briefing's coverage of the SpaceX deal. Anthropic has not publicly confirmed the figures.