The AI market's rapid expansion has sparked a massive increase in electricity demand, especially among data centers, over the past few years. That AI power boom is generating strong tailwinds for Constellation Energy (CEG -0.14%) and Vistra (VST -0.80%), two of the largest independent power producers in the United States.
Over the past three years, Constellation's stock has rallied 137%, and Vistra's stock has soared 330%. Let's see which of these AI-driven electrification stocks is a better buy right now.
Image source: Getty Images.
The differences between Constellation and Vistra
Constellation's nuclear, natural gas, oil, geothermal, hydro, wind, and solar facilities have a total capacity of 55 GW. That's enough power for roughly 27 million homes. It directly sells its power to residential and commercial customers through its eponymous retail electricity services.
Constellation operates the country's largest nuclear fleet with a total capacity of 22 GW. That business serves 80% of the Fortune 100, including the top hyperscalers, and drives most of its earnings growth. A major catalyst has been the Zero-Emission Nuclear Production Tax Credit (PTC), which was established under the Inflation Reduction Act of 2022. If power prices are too low, the PTC subsidizes its business, but if they're high, the PTC amplifies its gains.
NASDAQ: CEG
Key Data Points
Vistra operates natural gas, nuclear, coal, solar, and battery energy storage facilities with a total capacity of 44 GW, which can power 22 million homes. It sells electricity through its subsidiaries, including TXU Energy, Dynegy, Homefield Energy, and Ambit, as well as other utilities. Like Constellation, Vistra holds long-term power purchasing agreements (PPAs) with several tech titans. It also benefits from the PTC and other tax credits for renewable energy and storage providers.
However, Vistra's nuclear fleet, which accounts for only about 15% of its total capacity, is much smaller than Constellation's. It primarily relies on natural gas, which accounts for 62% of its capacity, as well as its coal-fired and renewable businesses to drive earnings growth.
NYSE: VST
Key Data Points
Which company is growing faster?
In 2025, Constellation's adjusted operating earnings rose 8%. For 2026, it expects that figure to grow 22%-33% to $11.50-$12.50 per share. At $256, it trades at 21 times the midpoint of that outlook. Analysts expect its adjusted earnings to rise 29% in 2026 and 10% in 2027.
Several catalysts should drive that growth: its 20-year PPA with Microsoft to restart Unit 1 at Three Mile Island (rebranded as the Crane Clean Energy Center), the scaling of its PPAs with Meta and Walmart, the full integration of Calpine, which it acquired this January; and capacity-boosting upgrades for its existing plants.
In 2025, Vistra's adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) from ongoing operations -- which is comparable to Constellation's adjusted operating earnings -- rose 5%. For 2026, it expects that figure to rise 15%-29% to $6.8-$7.6 billion. With an enterprise value of $65.7 billion, it trades at just nine times the midpoint of that outlook.
Analysts expect Vistra's adjusted EBITDA to grow 29% in 2026 and 5% in 2027. That growth should be fueled by its massive, AI-driven PPAs with Meta and Amazon, its planned takeover of Cogentrix, expected to close by the end of 2026, and Helix Digital Infrastructure -- a newly formed joint venture to develop AI data centers.
Which stock is the better buy right now?
Constellation and Vistra have both been under pressure over the past year as investors fretted over higher interest rates and a potential slowdown in AI spending. However, they're both still reliable long-term plays on the insatiable demand for more electricity.
If I had to pick one of these stocks to capitalize on the AI energy boom, I'd pick Vistra because it's more diversified, has more exposure to natural gas (the single largest source of electricity for U.S. data centers today) than Constellation, and its stock is fundamentally cheaper. Constellation is still a great nuclear play, but its stock doesn't seem like a screaming bargain yet.
