DeepSeek's arrival in January 2025 shook the AI world.

Over the course of less than 10 hours' trading, news that China had created a better AI mousetrap -- one that took less time and costs less money to build and operate -- subtracted $600 billion from the market capitalization of Nvidia (NASDAQ: NVDA). In the energy space, DeepSeek's deep-discount AI model convinced a lot of investors that there won't be as big a market for nuclear plants to power AI data centers as they had thought, either.

Shares of Constellation Energy (CEG 0.32%), whose groundbreaking plan to reopen Three Mile Island to provide nuclear power to Microsoft (NASDAQ: MSFT) data centers instantly made it the bellwether of the AI-nuclear industrial-complex, lost 21% of its market capitalization on Jan. 27. And Constellation stock is still down , actually trading 29% below its DeepSeek share price.

Should this fact frighten investors, or should we perhaps look at this as a second opportunity to buy into Constellation Energy stock before it goes back up?

Follow the leader

You and I may wonder about this question, but if you ask Constellation Energy, they've got no doubts about it: Constellation is still going all in on nuclear energy for AI.

Earlier this month, Constellation announced it will invest $100 million to upgrade its two-unit Calvert Cliffs nuclear power plant in Maryland. Its goal: to seek a renewal of the plant's operating licenses and to even increase future power output.

According to World Nuclear News, Constellation plans to use the plant's "annual refueling outage" as an opportunity to replace pumps, motors, valves, and control rod systems, and to overhaul the plant's 13 KV transformer as well. The company further intends to install $68 million worth of new electrical breakers to permit Calvert Cliffs to output 10% more power in the future. Once accomplished, each unit at the plan should be able to produce about 950 megawatts of continuous nuclear power, accounting for nearly 90% of all "clean" energy produced in Maryland.

Both units already have licenses permitting them to operate into the 2030s. If approved for an extension, both units could be operating well into the 2050s.

Is Constellation Energy stock a buy?

So Constellation seems very confident that nuclear power is the future, and it's making a sizable bet on that hunch. But what about you and me? Should we be investing alongside Constellation? More specifically, should we be investing in Constellation?

That's a harder call.

On one hand, Constellation Energy stock at its trailing price-to-earnings ratio of 20.7 doesn't seem especially expensive. The average stock on the S&P 500 today, after all, costs 29.8 times earnings!

This analysis starts to go awry, though, once you realize that the average S&P stock is expected to grow earnings at roughly 9.5% annually over the next five years. But despite all the talk about having AI drive insatiable demand for energy, analysts polled by S&P Global Market Intelligence put Constellation's long-term annual growth rate at a subpar 7.4%.

Which is to say, if Constellation stock looks a bit cheaper than average, it may be cheap for a reason.

Consider furthermore that, although Constellation has become the bellwether and standard-bearer for the idea that artificial intelligence growth entails growth in nuclear energy, Constellation is hardly the only electric utility that might benefit from this trend.

Better options than Constellation Energy

No. 2 nuclear operator Duke Energy (DUK 1.38%), No. 5 Dominion Energy (D 1.45%), and No. 4 Southern Co. (SO 1.70%) all sell for lower P/E ratios than does Constellation: 20.4, 20.8, and 22.3, respectively. (The No. 3 nuclear plant operator in the U.S. is the Tennessee Valley Authority, by the way, and you can't invest in it.) All of these competitors also pay significantly better dividend yields than Constellation's meager 0.6%, too.

If I had to pick just one nuclear energy stock to bet on, though, I think it would be Dominion Energy.

Priced about 21 times earnings, Dominion is on its face cheaper than Constellation. Wall Street analysts predict Dominion will grow faster, too, with the current consensus being a 17.5% long-term earnings growth rate. Best of all, Dominion pays a superior 4.7% dividend yield that's the best of the whole group, and nearly 8 times more generous than Constellation's dividend.

With plans to begin expanding into small modular nuclear reactors soon, too, Dominion looks just as likely to benefit from any increased demand for nuclear power, from artificial intelligence, as Constellation is.

At today's prices, I like Dominion better than Constellation.