New York, May 23, 2026, 18:05 (EDT)
- Constellation finished Friday at $294.07, gaining 2.9% for the day and up 12.2% since Monday’s close after a three-day run into the long weekend.
- PJM and Constellation have been told by the U.S. Energy Department to keep Eddystone Units 3 and 4 in Pennsylvania online until Aug. 22.
- U.S. stock markets including Nasdaq and NYSE won’t open Monday for Memorial Day. Markets reopen on Tuesday in the next regular session.
Constellation Energy finished the week strong, with shares climbing to $294.07 at Friday’s close, after bouncing back late in the week. The move came as new U.S. grid-reliability steps and talk around data center electricity demand returned to the spotlight. Shares picked up from $260.67 on Tuesday to $294.07 by Friday, according to company pricing.
Constellation is now a direct bet on the U.S. power market getting tighter: power demand keeps rising, while new supply comes slower, and the grid operator is working to hold on to power plants. The story for investors is straightforward—who has megawatts ready to go when big buyers like AI data centers call for power.
Late Thursday, there was company news as U.S. Energy Secretary Chris Wright issued an emergency order for PJM Interconnection to coordinate with Constellation, keeping Eddystone’s Units 3 and 4 operating past the original shutdown date. The order lets the units run until Aug. 22, according to Reuters. Wright told Reuters energy sources “perform when you need them most” are worth the most. Reuters
PJM’s push this week to bring forward a centralized power supply procurement to September 2026 gave the market a second catalyst. A capacity procurement pays generators to stay online—not just for the electricity they generate. Waiting until 2027 would raise “near-term reliability risk,” PJM Board Chair Paula Conboy said in a board letter dated May 19.
Other power stocks moved up as well. According to Barron’s, Constellation, Talen, Vistra and NRG each surged Wednesday after the PJM update. Shares of Constellation climbed 7.9%, Talen rose 9.5%, Vistra added 6.9% and NRG was up 8.3%.
Constellation expanded its fleet in this cycle after closing the Calpine acquisition on Jan. 7. The company said in a filing the deal brought in mostly natural gas, geothermal, battery storage and solar assets totaling about 23 gigawatts of capacity. That lifts Constellation’s overall fleet to 55 gigawatts.
Constellation has direct exposure to data centers. In the first quarter, the company signed a 380-megawatt deal with CyrusOne for a data center next to its Freestone Energy Center in Texas. A megawatt measures power capacity. Calpine has an exclusive deal for a second 380-megawatt phase, according to the filing.
Constellation posted first-quarter adjusted operating earnings of $2.74 a share earlier this month, sticking with its 2026 guidance of $11 to $12 a share. CEO Joe Dominguez said the focus is “on execution.” CFO Shane Smith said Constellation is “affirming our full-year guidance.” Constellation
Constellation gained 2.88% on Friday, according to MarketWatch, ahead of the S&P 500’s 0.37% move and the Dow’s 0.58% climb. The stock is still 28.74% below its 52-week high at $412.70. The overall market backdrop gave some support.
But policy risk is still on the table. PJM has warned that unless states create rules to make new data-center loads pay for the backstop procurement, “it is unclear to which customers” the costs would go. That could mean trouble with consumers and politicians. Constellation has told investors it’s exposed to swings in commodity prices, weather, fuel costs and policy, and said nuclear fuel markets can also face price and supply restrictions.
US equity markets are closed Monday for Memorial Day, so Constellation will trade next on Tuesday. Investors look to PJM’s updated Critical Issue Fast Path timeline, after the board said there won’t be a May 27 special members meeting. That meeting could be replaced by a session for new proposals.
