FuelCell Energy (NASDAQ: FCEL) shares surged more than 19% on heavy volume Friday.

Jefferies Financial Group upgraded the stock from hold to buy. The firm raised its price target to $24.00 from $16.00.

The upgrade follows an agreement with Fit Energy to supply up to 380 megawatts of power for data centers. Analyst Julien Dumoulin Smith noted the deal shifts the company from a show-me phase to an execution phase. Jefferies identified rising data center demand as a significant growth catalyst for the company.