Constellation Energy Corporation (NASDAQ: CEG) ended the holiday-shortened Christmas Eve session higher, then traded slightly softer in extended hours as U.S. markets headed into the Christmas Day closure. With liquidity thin and headlines still shaping the “AI power demand” narrative in U.S. electricity markets, investors are heading into the next trading session with a familiar checklist: power-market pricing, data-center demand, nuclear operating leverage, and deal execution (Calpine). [1]
Key takeaways after the bell (Dec. 24, 2025)
- CEG closed at $363.95 (+0.73%) in a session that ended early at 1:00 p.m. ET for Christmas Eve. [2]
- In after-hours trading (which also closed early), CEG was around $363.80 near 4:59 p.m. ET, down about 0.04% from the close. [3]
- The broader market finished higher, with the Dow and S&P 500 at record closing highs, but volumes were notably light in the shortened session. [4]
- The market is closed Thursday, Dec. 25 for Christmas; the next U.S. equity session is Friday, Dec. 26 (normal hours). [5]
CEG stock price after the bell: the Dec. 24 close, range, and after-hours trade
In the regular session that ended early, Constellation Energy stock:
- Closed: $363.95
- Day’s range: $359.00 to $364.56
- Volume: ~628K shares (light vs. normal days for many large-cap names, consistent with the holiday tape)
- 52-week range (context): $161.35 to $412.70 [6]
After the bell, CEG traded modestly lower into the end of the shortened extended session:
- After-hours (near 4:59 p.m. ET): ~$363.80 (about -0.04%) [7]
One important “mechanics” note for Christmas Eve: Nasdaq’s official trading alert for the holiday specifies that the Nasdaq Day Session ended at 1:00 p.m. ET and the Nasdaq Extended Session ended at 5:00 p.m. ET on Dec. 24—meaning after-hours price discovery was compressed and potentially less informative than on a normal day. [8]
Why Constellation Energy moved today: a quiet tape, but the same big theme
On Dec. 24, the broader market’s tone was upbeat. Reuters reported U.S. stocks closed higher, with the Dow and S&P 500 hitting record closing highs in a rally that unfolded during a holiday-shortened session with thin volumes—exactly the kind of environment where price moves can be exaggerated, spreads can widen, and single-name flows can matter more than usual. [9]
For Constellation, the “why” hasn’t fundamentally changed in late 2025:
- AI and data-center electricity demand remains the dominant narrative powering investor interest in nuclear and power-generation equities. [10]
- The market is also digesting how that demand surge is showing up in capacity pricing and grid reliability debates—issues that can directly influence forward power economics (and therefore valuations) for generators. [11]
A Dec. 24 market recap from GuruFocus framed the year’s power-sector strength around AI-driven electricity demand, explicitly naming Constellation Energy among companies perceived as beneficiaries of the trend. [12]
The “grid pricing” backdrop investors are watching: PJM capacity auction and AI rulemaking
If you’re looking for the most concrete, near-term fundamentals investors have been anchoring to in late 2025, it’s this: power-market pricing signals are flashing scarcity, especially in PJM (the nation’s largest grid). That matters for Constellation because it operates a large generation footprint in PJM zones.
1) Constellation’s PJM disclosure: all PJM plants cleared at the auction price
In an SEC filing dated Dec. 17, Constellation said each of its power plants located in the PJM market cleared in the 2027–2028 capacity auction, with clearing volumes shown across zones (including nuclear and fossil/other categories) at a listed $333 price in the table. The filing also notes the auction results take effect June 1, 2027, and that capacity revenues for nuclear units are included in the gross receipts calculation for the Production Tax Credit. [13]
This doesn’t immediately change 2025 or 2026 earnings, but it reinforces why investors keep paying attention to forward market structures: the market is trying to price multi-year power economics before they hit reported results.
2) Reuters: PJM capacity prices hit another record high
Reuters also reported PJM’s capacity auction prices hit a new record around $333.44 per megawatt-day, reflecting a supply-demand crunch and raising concerns about future utility bills—while simultaneously implying potential “windfall” economics for existing generators in constrained markets. [14]
3) FERC pushes PJM to develop clearer rules for AI-driven “co-located” data centers
On the policy side, Reuters reported FERC directed PJM to implement new rules governing the connection of AI-driven data centers and other large loads located near power plants, citing concerns about reliability and rising costs, and ordering PJM to revise tariff language viewed as unclear and inconsistent. [15]
For CEG investors, this is a “watch the process” item. Rule changes can influence:
- interconnection timelines,
- who pays for upgrades,
- and how power plants interact economically with large on-site or near-site loads.
Company-specific catalysts still “in play” heading into the next session
Even without a major new Constellation headline on Dec. 24 itself, several company-specific developments remain active inputs for the stock.
Calpine deal execution: progress made, but still a market focus
Constellation’s planned acquisition of Calpine has been one of the defining corporate stories for the company in 2025.
- Reuters reported on Dec. 5 that Constellation reached a resolution with the U.S. Department of Justice on conditions required to complete the $16.4 billion Calpine acquisition, and that FERC approved the deal on a condition involving divestitures of certain generating assets. [16]
- Reuters’ original deal story described the acquisition as positioning Constellation to become the largest U.S. independent power provider and highlighted Constellation’s view that demand growth is unusually strong, with expectations that the transaction could add materially to free cash flow (as discussed at announcement time). [17]
Why it matters before the next open: even in quiet tapes, merger-related newsflow (divestitures, financing steps, timelines, final conditions) can move the stock—especially when valuations across the sector are sensitive and liquidity is thin.
Debt exchange timeline linked to the Calpine transaction
On Dec. 23, Constellation Energy Generation announced it extended the expiration date of its private exchange offers and consent solicitations related to certain Calpine notes to Jan. 12, 2026 (from Jan. 8, 2026), and reported receiving the requisite consents for proposed amendments based on early tender results. The release also states the exchange offers are conditioned on consummation of the transaction. [18]
Why it matters now: this is the kind of “plumbing” item that can signal how financing and closing mechanics are progressing—and it gives the market a fresh date to keep on the calendar.
Nuclear fundamentals: license extensions and high-profile offtake deals remain a tailwind
Constellation’s nuclear fleet is central to the bullish thesis around the company as AI/data-center power demand rises.
- Reuters reported on Dec. 16 that the U.S. nuclear regulator approved 20-year license renewals for Constellation’s Clinton and Dresden facilities, and that Constellation expects to invest more than $370 million to relicense the plants to boost efficiency and ensure reliability. Reuters also noted the approvals allow Clinton to operate through 2047 and Dresden reactors through 2049 and 2051. [19]
- Reuters reported in November that the U.S. government loaned Constellation $1 billion to restart the reactor at the former Three Mile Island site, and referenced Constellation’s agreement with Microsoft tied to restarting the 835-megawatt reactor. [20]
These are not “today-only” stories, but they remain highly relevant because they reinforce the market’s working assumption: Constellation has scarce, long-lived, carbon-free generation that can be monetized in a world where new supply is hard to build quickly.
Forecasts and analyst outlook: what the Street is projecting for CEG
Analyst and forecasting dashboards (which compile published analyst research) continue to show a broadly constructive stance on Constellation Energy, though targets vary depending on the dataset and update cycle.
- StockAnalysis lists an analyst consensus of “Buy” and a 12-month price target around $392.93 (about +8% from the last price shown). [21]
- Investing.com lists an average 12-month price target around $405.49, with a high estimate of $481 and a low estimate of $342.23, alongside an overall “Buy” rating in its summary. [22]
How to interpret this heading into the next session:
- The consensus target band suggests analysts are not uniformly calling for another explosive leg up from here, even if they remain positive overall.
- The wide spread between low and high targets underscores the key debate: how much future AI-driven demand (and pricing power) is already in the stock, versus how much is still underappreciated.
Technical and positioning check: what indicators were signaling into late Dec. 24 / early Dec. 25
If you’re watching the stock from a technical lens into the next open, there are two practical realities:
- Holiday liquidity can distort signals (moves on light volume can reverse quickly when normal participation returns). [23]
- Many traders still use broad “dashboard” indicators for a quick read.
Investing.com’s technical dashboard showed a “Strong Buy” summary reading in an update timestamped early Dec. 25 (GMT), with RSI and multiple moving-average signals marked “Buy” in its table. [24]
Separately, StockAnalysis places CEG’s 52-week high at $412.70, putting the Dec. 24 close roughly in the neighborhood of about 12% below that high—close enough that the prior peak can matter as a psychological resistance area for momentum traders. [25]
What to know before the next market open: the checklist for Dec. 26
Because U.S. markets are closed on Thursday, Dec. 25, the actionable “before the open” setup is really about Friday, Dec. 26. [26]
1) Expect thin liquidity to linger—and watch for gaps
Christmas Eve already delivered low participation, and the first session after a holiday can produce price gaps—especially in high-beta themes like power/AI-adjacent names. Reuters explicitly flagged thin volume in the Dec. 24 session. [27]
2) Monitor Calpine-related headlines and court/regulatory follow-through
Even if nothing breaks overnight, investors may reprice probabilities around:
- divestiture execution,
- closing timing,
- and financing mechanics (including the exchange-offer timeline now running to Jan. 12, 2026). [28]
3) Keep one eye on PJM / data-center policy developments
The PJM capacity auction outcome (and Constellation’s cleared volumes disclosure) remains part of the sector’s valuation foundation in late 2025—and FERC’s push for new PJM rules around AI-related interconnections is a developing policy track worth watching. [29]
4) Don’t ignore the broader tape
Constellation can trade with the “AI complex” on risk-on days and with “utilities/energy defensives” on risk-off days. The market’s late-December rally backdrop—and rate expectations—still matter, even if CEG has strong company-specific narratives. [30]
Bottom line: CEG heads into the next session steady, with catalysts still active
Constellation Energy stock finished Christmas Eve up modestly and traded slightly lower after hours into the early close of the extended session. The bigger story heading into the next open isn’t a single after-hours tick—it’s whether 2026 brings incremental confirmation on the themes the market has already been paying for: tight capacity markets, durable nuclear economics, AI/data-center load growth, and clean execution on the Calpine transaction path. [31]
This article is for informational purposes only and does not constitute investment advice.
References
1. stockanalysis.com, 2. stockanalysis.com, 3. stockanalysis.com, 4. www.reuters.com, 5. www.nasdaqtrader.com, 6. stockanalysis.com, 7. stockanalysis.com, 8. www.nasdaqtrader.com, 9. www.reuters.com, 10. www.gurufocus.com, 11. www.reuters.com, 12. www.gurufocus.com, 13. www.sec.gov, 14. www.reuters.com, 15. www.reuters.com, 16. www.reuters.com, 17. www.reuters.com, 18. www.constellationenergy.com, 19. www.reuters.com, 20. www.reuters.com, 21. stockanalysis.com, 22. www.investing.com, 23. www.reuters.com, 24. www.investing.com, 25. stockanalysis.com, 26. www.nasdaqtrader.com, 27. www.reuters.com, 28. www.reuters.com, 29. www.sec.gov, 30. www.reuters.com, 31. stockanalysis.com
