Constellation Energy Corporation, the largest nuclear power plant operator in the U.S., is set to invest $10.4 billion during the 2026-2027 period to strengthen its position in the clean energy sector despite facing an 18.9% decline in share price this year. Following its $26.6 billion acquisition of Calpine, the company has received bullish ratings, including an Outperform from Evercore ISI with a $380 price target. Constellation's partnership with Microsoft to restart the Three Mile Island nuclear facility further solidifies its role in the evolving energy landscape.