Constellation Energy (CEG) Stock: Calpine Deal Milestones, Nuclear Restart Momentum, and What to Watch Next Week (Updated Dec. 13, 2025)
Constellation Energy Corporation (NASDAQ: CEG) wrapped up a volatile week in U.S. markets with a sharp Friday pullback—yet the bigger story remains the same: investors are trying to price a nuclear-heavy power producer at the center of two giant forces colliding at speed—AI-driven electricity demand and a regulatory/financing chess match around Constellation’s planned Calpine acquisition. Reuters Because today is Saturday, December 13, 2025, U.S. equity markets are closed. The most recent official close to reference is Friday, December 12. CEG stock price today: where Constellation Energy stands heading into the week ahead Constellation Energy stock last closed at $351.98 (Dec.