New York, January 8, 2026, 21:09 EST — Market closed
- CEG shares fell 4.8% to $322.54 in Thursday trading after Constellation said it closed the Calpine deal
- Company says the combined platform totals 55 gigawatts of generation capacity
- Next up: Calpine-note exchange offer deadline on Jan. 12; U.S. jobs report due Friday morning
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. 1
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 Joe Dominguez said, “This isn’t just about two great companies coming together — it’s about strengthening America’s future.”
Constellation in January 2025 announced a $16.4 billion cash and stock deal for Calpine, increasing to roughly $26.6 billion with debt. The company cited rising electricity demand and a shift to lower-carbon power as key factors behind the transaction.
Regulators conducted an extensive review of the merger. In December, Constellation agreed with the U.S. Department of Justice to sell the York 2 plant in Pennsylvania, the Jack Fusco Energy Center near Houston, and a minority interest in another Texas facility. The deal aimed to resolve competition issues in Texas and PJM, the mid-Atlantic grid operator.
Investors are monitoring the debt cleanup related to the deal. A Dec. 23 filing revealed Constellation extended private exchange offers—a debt swap—and consent solicitations for certain Calpine notes until 5 p.m. New York time on Jan. 12, following significant early tenders. 2
On Thursday, CEG opened at $336.51, dipped to $321.65, and then briefly rose above $340. Traders highlighted $320 as a key support level, with the stock trading close to that point.
But a larger footprint increases execution risk. Integration costs may exceed estimates, power prices can fluctuate, and disruptions at nuclear units could have a greater effect when expectations are elevated.
Traders faced macroeconomic risk on Friday ahead of the U.S. December employment report, set for release at 8:30 a.m. ET on Jan. 9. A surprise in the data could shift rate expectations and affect utility and power stocks before markets open.
