Shares of Constellation Energy Corp (CEG) are surging 5.25% in Tuesday's pre-market trading following the company's mixed first-quarter 2025 results and reaffirmed full-year guidance. The power generation company's strong revenue performance and operational efficiency appear to be outweighing a slight earnings miss.

Constellation reported Q1 adjusted earnings per share of $2.14, up from $1.82 in the same quarter last year but slightly below the analyst consensus of $2.18. However, the company's revenue soared to $6.79 billion, marking a 10.2% year-over-year increase and significantly beating the Wall Street estimate of $5.56 billion. This robust top-line growth seems to be the primary driver behind the stock's pre-market rally.

Despite the challenging interest rate environment, Constellation reaffirmed its full-year 2025 adjusted earnings guidance range of $8.90 to $9.60 per share, demonstrating confidence in its ongoing operations. The company also reported strong operational performance, with its nuclear plants achieving a 94.1% capacity factor and natural gas operations attaining a 99.2% dispatch match rate. Additionally, Constellation confirmed that its $16.4 billion acquisition of Calpine remains on track to close by year-end, potentially creating the leading U.S. retail power supplier. These factors collectively appear to be fueling investor optimism, overshadowing the slight earnings miss and driving the stock's significant pre-market gains.