Constellation Energy (CEG) Stock After Hours Today (Dec. 17, 2025): Why Shares Fell and What to Watch Before Thursday’s Open
Constellation Energy shares fell 6.74% to $340.97 Wednesday, then rebounded 2.23% in after-hours trading to about $348.58 after new grid-market headlines. The stock swung between $372.00 and $334.18 on heavy volume. The drop followed negative sentiment in AI-related stocks and concerns over AI infrastructure spending. PJM capacity auction news arrived after the close.