Nuclear energy stocks were among the energy sector's best-performing stocks in 2025.
Oklo, for instance, ended the year with a triple-digit gain, while uranium enricher Centrus Energy and uranium miner Cameco both had blockbuster performances.
Even the VanEck Uranium and Nuclear ETF (NLR 0.22%), a nuclear energy exchange-traded fund, ended the year with a 12-month gain of more than 50%.
One company that continues to stand out for its dominance in the industry is Constellation Energy (CEG +0.29%). Indeed, if I had to pick one nuclear energy stock to buy and hold for the next 10 years, Constellation would top the list. Here's why.
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A nuclear advantage that can't be replicated quickly
Constellation Energy may not have the exciting growth potential of a start-up like Oklo. But it has something Oklo doesn't have yet, nor will likely have for several years: operating nuclear power plants.
Indeed, Constellation operates the largest nuclear fleet in the U.S., and it has signed several contracts that will extend over the next decade.
NASDAQ: CEG
Key Data Points
In June 2025, it announced a 20-year agreement with Meta Platforms tied to the full output of its Clinton Clean Energy Center starting in 2027. It has also made moves to restart the former Three Mile Island Unit 1 site (now Crane Clean Energy Center) with support from Microsoft.
Constellation has also completed its acquisition of Calpine, which makes it the U.S.'s largest producer of electricity.
Looking ahead, I wouldn't rule out the possibility of Constellation developing its own next-generation reactors. Like Oklo and NuScale, which are designing small reactors, Constellation could develop its own novel technology to keep up with demand from artificial intelligence (AI) data centers. In fact, CEO Joe Dominguez has already signaled that the company might consider next-generation nuclear plants on existing sites.
Again, Constellation likely won't deliver a start-up-style upside over a 10-year period. But with operating assets and long-term contracts, it look well positioned to grow over the next decade.
