Constellation Energy (CEG) shares staged an impressive 8.0% advance during the holiday-shortened trading week, closing Thursday at $274.06. The rally outpaced the S&P 500's 1.08% rise on the final session, with volume surging to approximately 7.0 million shares—roughly double the 50-day average, according to MarketWatch data. U.S. exchanges were shuttered Friday for Juneteenth, making Thursday's close the last mark before the weekend.
The catalyst came from the Federal Energy Regulatory Commission (FERC), which on June 18 ordered six regional grid operators to justify or revise tariffs governing grid access for large energy users, including AI data centers. The move aims to shorten connection queues for power-hungry customers while determining cost allocation for grid upgrades. For Constellation, which operates the largest U.S. nuclear fleet, faster grid access could translate into contracted revenue from surging AI-driven electricity demand.
Despite the weekly gain, the stock remains 33.6% below its 52-week high of $412.70, reached on October 15. This gap underscores investor caution: while the nuclear-and-AI narrative is compelling, execution risks—such as regulatory delays, cost overruns, or timeline slippage—can trigger sharp pullbacks. The market is pricing in a story of delivery, not just promise.
The rally extended beyond Constellation. Peers Vistra (VST) rose 3.1%, and NRG Energy (NRG) gained 2.2% in the latest regular session, reflecting broad-based enthusiasm for wholesale power producers with exposure to data center demand. Constellation's expanded footprint, following its January acquisition of Calpine, positions it as the nation's largest electricity producer, a scale that could prove pivotal in meeting AI infrastructure needs.
In May, Constellation reported first-quarter adjusted operating earnings of $2.74 per share and reaffirmed full-year 2026 adjusted earnings guidance of $11 to $12 per share. "America needs reliable, clean power," CEO Joe Dominguez said at the time, encapsulating the bull case. However, the company must integrate Calpine, maintain plant reliability, and convert regulatory tailwinds into tangible deliveries.
Analysts have echoed this sentiment. Melius Research analyst James West described Constellation as "well-positioned to supply rapidly growing data center demand in 2026," citing its expanded natural-gas and ERCOT exposure from the Calpine deal. ERCOT, Texas's main power grid, is a critical market as data center developers seek both land and electricity. Texas regulators approved ERCOT's "Batch Zero" process on June 18 to study large-load projects of at least 75 megawatts, with Reuters reporting over 438,000 megawatts of large-load requests under review—about 89% from data centers. While not all projects will materialize, the sheer volume underscores the market's focus on power supply.
Looking ahead, investors will monitor Constellation's plan to restart the former Three Mile Island Unit 1, now the Crane Clean Energy Center. FERC recently granted a waiver allowing certain grid rights to transfer from the Eddystone gas plant to the nuclear site, with Constellation targeting a restart next year. However, the setup carries risks: regulators are also focused on shielding households from higher grid costs. If upgrades stall, customer resistance builds, or Crane faces delays, Constellation's valuation multiple could face renewed pressure. At current levels, the stock is no longer a forgotten utility—it's an execution story.
