Constellation Energy Corporation stock slides after Calpine deal closes — here’s what investors watch next
New York, January 8, 2026, 21:09 EST — Market closed Constellation Energy Corp (CEG) shares dropped 4.8% to $322.54 on Thursday following the completion of its acquisition of privately held Calpine from Energy Capital Partners. The deal increases the combined generation capacity to 55 gigawatts, making Constellation the largest electricity producer in the United States, the company said. Constellation Markets concentrate on one main issue: firm power. Data centers vie for a steady supply while the grid’s capacity to meet peak demand declines. Constellation plans to combine nuclear “always on” generation with Calpine’s natural gas and geothermal assets. Chief Executive