Nuclear energy is back.

After years of stagnation — years, however, of quiet innovation — nuclear companies have come roaring back to life. The reason isn’t hard to see. Nuclear offers carbon-free electricity that can run continuously, something solar and wind can’t promise on their own. And in a world facing rising electricity demands, especially from artificial intelligence (AI) data centers, the reliability of nuclear suddenly matters.

A number of nuclear start-ups have captured investors’ attention with ambitious and innovative ideas. Think, for example, of the small reactor designs of NuScale Power (SMR 4.31%) and Oklo (OKLO 3.63%) or the portable reactors of Nano Nuclear Energy (NNE 3.77%).

These companies are working on some exciting technology, but none match the scale and earnings power of clean energy giant Constellation Energy (CEG +0.56%). Indeed, if you were to own just one nuclear energy stock, Constellation is a compelling first choice. Here’s why.

Today’s Change

(0.56%) $1.61

Current Price

$288.96

Key Data Points

Market Cap

$90B

Day’s Range

$285.50 – $292.10

52wk Range

$161.35 – $412.70

Volume

142K

Avg Vol

2.9M

Gross Margin

19.30%

Dividend Yield

0.54%

Not a nuclear start-up, an established giant in nuclear energy

The nuclear start-ups mentioned above — Oklo, NuScale, Nano — are early-stage growth stocks. None are generating meaningful revenue. Only one — NuScale — has received approval from the Nuclear Regulatory Commission (NRC) for its reactor design, while Oklo and Nano are still in the thick of the licensing process.

Constellation, by contrast, already operates a large fleet of nuclear power plants. In fact, it operates the largest fleet of nuclear facilities in the U.S.

Image source: Constellation Energy.

The company has secured major deals with tech giants, including a 20-year contract from Meta Platforms for the full output of the Clinton nuclear plant and involvement from Microsoft in restoring the old Three Mile Island reactor to full functionality.

Constellation is profitable, with strong recent earnings growth. Its trailing-12-month revenue reflects a company that has clearly benefited from rising power demands, with future-12-month estimates that still dwarf revenue expectations for Oklo, Nano, and NuScale.

CEG Revenue (TTM) data by YCharts

Part of Constellation’s strength lies in its business model. Unlike most utilities, which operate as regulated regional monopolies, Constellation functions primarily as an unregulated power supplier. This means it can sell electricity at market rates rather than abide by government-set prices.

In practice, this structure could allow for more upside opportunity when prices are strong, though, at the same time, it also introduces risk. While current trends in electricity are favorable, the power market can be volatile, and lower power prices in key regions could strain margins and lead to uneven quarterly results.

Constellation could also be facing a potential political risk in its mid-Atlantic market. President Donald Trump, along with local governors in that region, appear aligned on a plan that would cap prices on existing power sources. While details are still uncertain, a move in that direction could constrain Constellation’s upside in that region.

Constellation stock trades at about 35 times trailing earnings and more than 7.5 times book value. Both of these signal a highly valued energy company with a lot of expectation already baked into the price.

Opportunity for growth remains, especially if electricity demands from AI accelerate over the next five years as many forecasts suggest. The stock isn’t without risks, but it carries less execution risk than most nuclear start-ups, like Oklo. That said, investors who want nuclear exposure without the volatility of a single stock may be more interested in a nuclear energy exchange-traded fund (ETF) instead.