Anthropic has agreed to pay about $9.1 billion over 20 years for 191 megawatts of data center capacity at Riot Platforms' campus in Rockdale, Texas. Bloomberg was first to identify Anthropic as the tenant, on Monday evening, a few hours after Riot disclosed the lease alongside its second-quarter results and described the customer only as a leading frontier AI lab.
The figure to watch is not the $9.1 billion. It is the 191 megawatts. A megawatt is a measure of electricity, and in this context it describes how much power a site can pull from the grid continuously, which in turn sets how many chips can run there. Riot's 191 megawatts is roughly what 143,000 homes draw at any given moment. Anthropic's problem for the past year has not been money. It has been finding sites with that kind of grid connection already built, which is why the company still limits how much its paying subscribers can use its most capable models.
That explains the counterparty. Bitcoin miners spent a decade collecting cheap power contracts, substations and grid interconnections in places like rural Texas, which are exactly the assets AI labs need and cannot build quickly. With bitcoin trading near half its October 2025 high, that power is now worth more leased to an AI company than spent mining.
Reduced to a sentence, the news is that Anthropic has struck "a $9.1 billion, 20-year deal with Riot Platforms for 191 megawatts of AI data center capacity." Until Monday, Rockdale was a mining campus with one modest AI tenant, a 25-megawatt lease with AMD that Riot announced in January. It is now committed, across most of its capacity, to a single AI customer through June 2048. For a company whose revenue used to rise and fall with the price of bitcoin, that is a different business entirely.
What Riot still has to build
None of the capacity exists yet. Riot expects to have 96 megawatts running by December 2027 and the full 191 megawatts by June 2028, and it has taken a $573 million interim financing facility from Morgan Stanley to cover early construction while it works toward a permanent investment-grade credit backstop, according to the company's second-quarter release. Riot projects average annual net operating income of $365 million to $411 million once the site is full.
The quarter underneath the announcement was weaker. Revenue rose 14% to $174.2 million, of which $23.2 million came from data centers and $113.7 million from mining. Riot swung to a net loss of $237.2 million, or $0.68 per diluted share, from net income of $219.5 million a year earlier, and its bitcoin treasury fell from 15,680 coins to 11,380 as it sold to fund construction.
The stock gave back most of its jump
Riot closed at $19.40 on Monday, down 5.46%, then rose about 25% in after-hours trading once the lease was disclosed. On Tuesday it traded as high as $23.70 and closed near $20.24, up roughly 4%. Analysts at Cantor Fitzgerald, Bernstein and Piper Sandler all raised their price targets that morning. The intraday fade is the market pricing execution risk: the revenue arrives in 2028, the construction bill arrives first.
Anthropic has not confirmed anything
Anthropic has not commented publicly, and it does not disclose what it pays for compute in total, so there is no public figure for how much of its budget the Riot lease represents. What is visible is the pace. TeraWulf announced a 20-year lease with Anthropic on July 6 covering 401 megawatts in Hawesville, Kentucky, worth about $19 billion. Bloomberg reported on August 4 that Anthropic had signed a six-year, $10 billion deal with Volta Infra Holdings for capacity in Norway. The New York Times reported in July that Anthropic was in early talks to rent up to $10 billion of Meta's spare capacity over two years.
Anthropic is now buying electricity in 20-year blocks from a company that signed its first AI lease in January, and paying for buildings that will not be finished until 2028. That is either a sharp read on where demand is going, or a very long time to be locked in.