Nuclear Stocks Are Soaring. We Size Up the Prospects for 3 New Ones.

Terrestrial Energy, which is planning to go public, is teaming with Texas A&M University on a planned commercial modular reactor. (Terrestrial Energy )

More than 80 companies around the world are developing new kinds of nuclear reactors, hoping to get their hands on the tens of billions of dollars that utilities are expected to spend on reactors in the coming decade. But there are only three pure-play stocks in the U.S., making it difficult for investors to buy into the trend.

That could change soon. Three more companies working on building new kinds of small reactors—Terra Innovatum, Terrestrial Energy, and Eagle Energy Metals—have filed to go public via SPACs, or special purpose acquisition companies, and they intend to start trading by the end of the year.

The three are entering public markets at a time of enormous enthusiasm for new nuclear technologies, which are seen as one solution to the growing electricity demand from artificial-intelligence data centers and other industrial plants. Amazon and Alphabet’s Google have already made deals with unproven nuclear companies to buy power from their reactors. Investors are plowing money into the industry. Upstart nuclear stocks Oklo , NuScale Power , and Nano Nuclear Energy have all more than tripled since their stock debuts.

All three of the coming SPACs have designed nuclear reactors that are expected to be smaller than the enormous nuclear plants in operation today, and use newer technology that’s meant to be safer and more nimble than current reactors.

There are dozens of different designs out there, but they’re generally lumped together as “small modular reactors”—modular meaning that most of them can be built in pieces in a factory rather than having to be custom-built on site for each nuclear plant. Presumably, that process will make them cheaper to construct than big plants, though there’s no evidence of that yet. Only a small handful have been built anywhere, and none in the U.S.

Terra Innovatum, which is based in Italy, aims to sell very small reactors, with just 1 megawatt of electric capacity, or enough to power a few hundred homes. Existing U.S. reactors tend to provide at least 800 megawatts of power. Terra Innovatum’s reactors are built in cubes that measure 10 meters, or about 33 feet, on each side, allowing them to be transported and placed almost anywhere, the company says. They could be deployed alone or in bunches, allowing them to power everything from a hotel to an industrial facility or a mine in a remote location.

Terrestrial Energy, based in Charlotte, N.C., is designing reactors with the capacity to provide about 390 megawatts of power. The reactors use molten salt instead of water to power the turbines that turn nuclear energy into electricity, and to cool the reactions. Terrestrial CEO Simon Irish says that molten salt is a much more efficient fuel source and coolant than water, which all existing U.S. reactors use today.

The company acknowledges in securities filings that its novel process could delay regulatory approval, but it also has attracted partners that could advance the technology faster. Terrestrial was one of 10 companies chosen by the U.S. Department of Energy last month for a pilot reactor program that aims to get small versions of the reactors operating as soon as July 2026.

Eagle Energy Metals, whose corporate office is in Reno, is both a reactor-developer and a uranium miner. The company’s most important asset is a mine in Oregon that it calls the “largest mineable, measured and indicated uranium deposit in the United States.” The mine will still take years to develop. CEO Mark Mukhija said in an interview he doesn’t expect commercial operations to start until 2032. But once it starts up, it could produce between one and four million pounds of uranium a year, according to initial estimates cited by Mukhija. That compares to total current U.S. production of less than one million pounds.

The company also licensed a small modular reactor design based on liquid metal-cooled reactors from an arm of the University of New Mexico. It says the business is very promising but will be a secondary priority to the mine.

Given the modular nuclear industry’s limited track record, and the fact that none of these companies have working or licensed reactors, it’s tempting to dismiss the whole small nuclear trend as too speculative. Nuclear is by definition a risky technology, and the companies are all experimenting with methods that haven’t been commercialized yet.

Chris Gadomski, the lead nuclear analyst for Bloomberg New Energy Finance, said in an interview that each of the companies’ methods raise practical questions. In Eagle’s case, he considers the idea of a uranium miner also developing reactors to be an awkward fit, as the two businesses have little in common. For Terra, he worries that it will be expensive to provide security for tiny reactors spread out in several places. And with Terrestrial, he understands the theoretical benefits of molten salt technology but thinks it could be trickier in practice. Its lack of operating history means investors will be taking “first of its kind” risk.

On top of that, the three companies are going public using a method that’s had a very mixed track record.

SPACs are investment vehicles that can seem like a way to back into a public listing. A SPAC sponsor—often a financial firm or fund manager—raises money from investors with the intention of eventually merging with a private company and taking it public. Once a merger is completed, shares start to trade on public markets. Historically, the SPAC process has been considered less-rigorous and time-consuming than the traditional IPO method, although beefed-up SEC requirements have since closed some of the gap.

Though they’ve been around since the 1990s, SPACs skyrocketed in prominence in 2020 and 2021, an era of aggressive risk-taking. They also gained a bad reputation. The average SPAC that came public between 2017 and 2022 returned negative 61% for an investor who held it for three years, according to one academic study published last year. SPACs fell out of favor by 2022 and issuance has been down, but 2025 has seen a resurgence. More SPAC teams have launched IPOs this year than any year since 2021, according to SPAC Insider.

While SPACs overall have struggled, nuclear stocks have been one notable exception. Oklo and Nuscale went public using the SPAC process and have soared since, despite neither of them having built a reactor yet. There is simply so much excitement about the industry, and so few ways to play it.

Irish, the CEO of Terrestrial Energy, said that he chose the SPAC route for several reasons. “In certain circumstances, they serve a unique and valuable role—and that is the ability to bring companies into public markets in a way which is perhaps less risky and faster than would be the case in a conventional IPO,” he said.

This next tranche of nuclear stocks may not enjoy the same big returns as the first group. Oklo, NuScale and Nano all benefited from the fact that they were the only game in town. “That scarcity does lead to better performance,” said Chris Sorrells, the CEO of Spring Valley Acquisition Corp., the SPAC sponsor taking Eagle public. Sorrells also took NuScale public.

Once there are more options, investors will be able to be choosier about which companies they want to invest in, Sorrells said.

Gadomski thinks that there are all sorts of reasons to doubt nuclear start-ups, because implementing the technology is much harder than developing it. “I kind of just scratch my head and wonder when it’s going to end, when it’s going to fall apart,” he said. But he’s clear-eyed about the investor demand, and doesn’t see any immediate signs of it slowing down. So far “the investors who participate in these things are very, very happy.”

Write to Avi Salzman at avi.salzman@barrons.com