Anthropic Just Signed the Deal Microsoft Walked Away From

Anthropic signed a $45 billion, six-year deal with Nscale, a UK-based AI infrastructure company, for 460 megawatts of compute capacity at a data center campus in West Virginia. The compute will run on Nvidia’s next-generation Vera Rubin chips and is expected to come online in late 2027. On its own, that’s just another entry in the AI compute arms race — Anthropic has now signed roughly $80 billion in infrastructure commitments this month alone, including the Theseus joint venture with Macquarie and GIC and a separate $10 billion deal with Norwegian startup Volta. What makes this one worth a closer look is who had the site first.

Microsoft’s leftovers

Nscale’s West Virginia campus — an 8-gigawatt buildout called Monarch Compute, with more than $20 billion in planned capital investment — was originally Microsoft’s. Microsoft signed a letter of intent in March for up to 1.35 gigawatts of capacity there, then quietly walked away from the commitment over the summer. No public explanation has surfaced for why Microsoft backed out, though the pattern fits a year in which hyperscalers have been more willing to cancel or scale back data center leases than they were in 2024 and 2025, when the assumption was that any capacity you could get your hands on was capacity worth having.

Anthropic stepped into the gap. Nscale still had a fully permitted, partially financed site with power infrastructure in progress, and Anthropic needed compute badly enough to take a large chunk of what Microsoft had given up. The $45 billion contract is now the single largest commitment in Nscale’s reported $51 billion revenue backlog — meaning one abandoned Microsoft deal effectively became the anchor tenant for another company’s infrastructure company.

Why this is an IPO story as much as a compute story

Nscale has hired Goldman Sachs and JPMorgan to manage a US IPO targeting roughly $3 billion, and the timing of the Anthropic deal — landing just as the IPO prospectus is being shopped to investors — is not a coincidence. A six-year, $45 billion contract from one of the two or three companies capable of writing checks that size is exactly the kind of revenue visibility that makes a data center operator’s IPO easier to price. Nscale gets to walk into its roadshow with a backlog anchored by a name-brand AI lab instead of a portfolio of speculative leases.

That’s the same logic behind Theseus: Anthropic doesn’t want to own data centers, but every entity that does want to own them needs an anchor tenant to justify the capital, and Anthropic’s compute hunger makes it an unusually good one. The company is effectively becoming a credit signal for infrastructure investors — sign Anthropic, and the rest of the financing gets easier. Whether that’s a sustainable position depends entirely on whether Claude’s revenue growth actually catches up to the lease payments piling up across Theseus, Volta, and now Nscale, a gap we’ve flagged before as the unresolved bet sitting underneath all of these announcements.

The pattern, zoomed out

None of these deals individually says much about whether the AI infrastructure buildout is rational. What’s notable is the shape they keep taking: a lab commits to renting capacity for the better part of a decade, an infrastructure company or consortium takes on the capital risk of building it, and the deal doubles as a financing instrument for whoever owns the concrete and the power contracts. Microsoft’s exit from Monarch Compute is a reminder that these commitments aren’t permanent — a letter of intent can evaporate over a summer — but Anthropic’s willingness to absorb an abandoned Microsoft footprint suggests the appetite for compute, at least on Anthropic’s side, hasn’t cooled at all. If anything, being the company that shows up to take the deal a hyperscaler walked away from is starting to look like a deliberate strategy rather than a coincidence.