Vistra Corp. stock rose 10.8% in morning trading Tuesday after the U.S. Department of Energy's Office of Energy Dominance Financing confirmed a conditional loan commitment of up to $4.2 billion for nuclear capacity upgrades at three company facilities.

Energy Secretary Chris Wright announced the commitment during a visit to Vistra's Perry nuclear complex northeast of Cleveland. The loan will finance modernization at Perry and Davis-Besse in Ohio and Beaver Valley in Pennsylvania.

The projects aim to add 433 megawatts of new zero-carbon baseload capacity and preserve nearly 4 gigawatts of existing nuclear output. The upgrades will extend plant operating licenses by 20 years. The conditional loan includes an option to finance future uprates at Vistra's Comanche Peak facility in Texas.

BMO Capital maintained its Outperform rating on the stock while lowering its price target to $210 from $231. Call-option volume increased, reflecting institutional and speculative interest.