ERock shares rose after the company said it signed a deal to provide power to Anthropic.
The stock climbed about 16% to $13.00 in premarket trading Wednesday. Through the previous close, shares were down 40%.
The onsite power provider said it executed a 470-megawatt equipment purchase order with Anthropic during the quarter and extended production commitments with the artificial-intelligence leader into 2028.
The deal increased ERock's contracted power system sales backlog to $1.7 billion.
"We believe AI infrastructure is fundamentally reshaping power markets, and the need for rapid, utility-grade power continues to accelerate," ERock Chief Executive John Carrington said.
Revenue in the second quarter fell 42% to $39.9 million, ahead of the $20.4 million analysts expected.
ERock narrowed its loss to $67.7 million, compared with a loss of $8.0 million the year before.
It now expects full-year revenue to be $435 million to $465 million, while analysts are projecting $448.3 million.