Artificial-intelligence leader Anthropic signed a 20-year lease with Riot Platforms for a data center in Rockdale, Texas.

The lease includes 191 megawatts and is expected to generate $9.1 billion in its initial term.

Riot's stock gained 17% to $22.61 in premarket trading Tuesday. Through the prior close, shares were up 53% from the start of the year.

The lease also includes two five-year extension options at the tenant's election, which would bring the total contract value up to $16.1 billion, Riot said in a release Monday.

Together with Riot's lease with Advanced Micro Devices, which it announced in January, the digital-infrastructure company has contracted 241 megawatts of capacity with two of the biggest AI companies.

The latest lease comes as the company has been working to pivot from a focus on Bitcoin mining to digital infrastructure for AI, as investors increasingly favor AI development over cryptocurrency.

Activist investor Starboard Value has been pushing for Riot to convert some of its bitcoin-mining facilities into data-center capacity for AI hyperscalers. The investor took a significant stake in Riot in late 2024.

The company aims to deliver the first 96 megawatts of capacity in December 2027, with the remaining capacity becoming available in June 2028, executives told analysts on a call.

Riot has secured a $573 million interim financing facility from Morgan Stanley, which will cover initial development while an investment-grade backstop is finalized, the executives said.

Riot's total sales in the second quarter were $174.2 million, ahead of the $154.3 million analysts expected, according to FactSet. Riot's loss per share was 68 cents, wider than the 30-cent loss that analysts forecasted.

Anthropic meanwhile has had an insatiable appetite for data-center space, as it aims to maintain its foothold as a frontrunner in the AI race. Its Claude models gained greater traction this year, becoming a bigger threat to rivals such as OpenAI's ChatGPT and Google's Gemini.

The AI company, which is aiming to go public this fall, has signed other major data-center lease deals, including an agreement in May to pay roughly $1.25 billion per month to lease from SpaceX.