Riot Platforms has identified its previously unnamed "Frontier AI Lab" tenant as Anthropic. The bitcoin miner disclosed the identity of the Claude developer in its quarterly report filed Wednesday, naming Anthropic as the counterparty behind a 15-year lease worth about $28 billion at its Corsicana, Texas campus. The company's results release published the same day had described the tenant only as a "leading Frontier AI Lab."

The 10-Q is more specific. It states that a Riot subsidiary signed the lease on Oct. 28 "with Anthropic PBC (the 'Frontier AI Lab')," and that the deal became binding on Nov. 4 after Riot's board approved it and outside consultants signed off on the technical specifications.

The filing applies the same defined term to the tenant of Riot's 191 MW Rockdale lease, signed in August. That makes Anthropic the counterparty on 1,101 MW of the 1,151 MW Riot has contracted. AMD holds the other 50 MW. The disclosure also fits a broader industry pattern: bitcoin miners with large power portfolios are leasing capacity to AI companies, which prize energized sites and grid interconnections because new capacity of that scale can take years to bring online.

Lease economics

The Corsicana lease covers 910 MW of critical IT capacity across the whole campus. Base rent starts at $130 per kilowatt per month and rises 3% a year. At that starting rate, the full 910 MW would generate roughly $1.42 billion a year. Riot puts average annual rent at about $1.8 billion over the initial term, or roughly $54 billion in total if Anthropic exercises both five-year extensions.

Riot's 12% clause

The detail drawing the most attention sits in the financing terms. Riot agreed to reimburse Anthropic up to $4 million per megawatt for the data center modules the tenant installs, or up to about $3.6 billion across the full 910 MW.

That reimbursement depends on Riot raising money "on market terms reasonably acceptable to it." If that financing is not available, the 10-Q says, Riot will instead give Anthropic rent credits that amortize the amount "plus interest at 12% per year" over the rest of the initial term. In that scenario, Anthropic would effectively finance the build itself and recover the cost out of rent at a double-digit rate — well above what investment-grade corporate borrowers typically pay.

Riot's base case is different. The company expects to fund the reimbursements with non-recourse project debt — borrowing backed by the project's own cash flows rather than Riot's balance sheet — sized to the contracted rent, and it puts the total capital requirement at about $6 million per MW, or $5.5 billion. It said it does not currently expect to issue equity for the project.

Deadlines and exits favor the tenant

The lease places most of the delivery risk on Riot. Capacity arrives in three phases: 400 MW, with a first block targeted for June 28, 2027; 200 MW starting Dec. 24, 2027; and 310 MW on July 30, 2028.

If Riot delivers more than 60 days late, Anthropic earns escalating rent credits capped at 270 days of base rent for the undelivered blocks. If a phase is not delivered within 270 days of its target, Anthropic can terminate the lease for that phase on 30 days' notice, with extensions for force majeure of up to 365 days.

Riot also cannot curtail Anthropic's power load or enroll the site in voluntary demand response programs without consent — a notable limit for a company that built its mining business partly on selling power back to the Texas grid. A change of control involving certain restricted parties would let Anthropic terminate the lease or buy Riot's interest in the premises at 95% of fair market value. Riot's own right to terminate is limited to uncured payment defaults and bankruptcy events.

Less bitcoin on Riot's balance sheet

The data center build is why the company has been selling bitcoin all year. It sold 20,264 BTC for about $1.5 billion in the first nine months of 2026, starting with 3,778 coins in the first quarter, and ended September with 2,418 BTC worth $202 million.

The 10-Q adds that the company expects to "continue to sell substantially all of the bitcoin we mine" and does not expect to accumulate significant bitcoin holdings in the near term.

That leaves Riot on a different path from miners such as American Bitcoin, which posted a third-quarter profit this week largely on gains in its bitcoin holdings. The test for Riot now is whether lenders fund the Corsicana build on terms that keep the 12% clause on paper only.

This article first appeared on Bitcoin Magazine and was written by Micah Zimmerman.