Oklo (OKLO 1.78%) and Nano Nuclear Energy (NNE +0.80%) are both pre-revenue nuclear start-ups chasing the same multitrillion-dollar opportunity: small nuclear reactors that could one day provide clean, always-on power to artificial intelligence (AI) data centers and other power-hungry customers.
Between the two, Oklo has the edge on partnerships, while Nano's valuation looks more reasonable. Let's take a closer at both to see which one is the better nuclear energy stock today.
Image source: Getty Images.
Oklo: A rich valuation with big-name backers
Oklo is designing a small nuclear reactor called an Aurora powerhouse. These reactors are engineered to run on both recycled fuel and high-assay low-enriched uranium (HALEU), a one-two punch that could make them more efficient, more flexible, and less dependent on the traditional nuclear fuel supply chain.
Oklo's strength is its partnerships. Never mind early backing by OpenAI CEO Sam Altman, Oklo now has major partnerships with Meta Platforms, Switch, Equinix, Nvidia, Vertiv, Liberty Energy, Blykalla, and RPower.
The biggest opportunities for future revenue growth are the first three -- Meta, Switch, and Equinix -- which together equal about 14 gigawatts (GW) of potential power demand, or enough to require about 187 full-sized 75 megawatt (MW) Aurora powerhouses, if Oklo were to supply it all.
NYSE: OKLO
Key Data Points
If we assume about $40 to $90 per megawatt-hour, Oklo's stated target price range, a full-sized 75 MW powerhouse could generate about $26 million to $59 million in annual revenue. At that rate, its 14 GW backlog clocks in around $4.9 billion to $11 billion -- still below its $12.5 billion market cap.
With a price-to-book ratio around 8 and zero revenue to its name, Oklo already commands a premium valuation. It's not cheap, but the size of its potential demand explains why investors are still willing to pay up.
Nano: An earlier play in a burgeoning industry
Nano Nuclear Energy is also designing small nuclear reactors. Like Oklo, the company is pre-revenue and lacks the regulatory approval to operate commercially.
Nano doesn't have as many star-studded partners as Oklo, but it does have a fairly big one: Super Micro Computer (SMCI +11.59%). Earlier in May 2026, the two companies signed a memorandum of understanding to deploy Nano's microreactors for Super Micro Computers' data centers.
Although it's unclear what the revenue potential could be, the partnership is a good sign that customers are willing to explore Nano's technology before it has even reached regulatory approval.
NASDAQ: NNE
Key Data Points
On that front, however, Oklo appears to be ahead. It's had a longer relationship with the U.S. Nuclear Regulatory Commission (NRC), and it's currently working with the agency to build its first powerhouse at the Idaho National Laboratory. Last week, the NRC approved the Principal Design Criteria (PDC) topical report for its Aurora powerhouse. While that doesn't mean the reactor itself is licensed, it does set a safety framework that can be referenced in future applications, thus reducing repeat work.
Nano, for its part, has started building a research reactor for the University of Illinois. Although it won't generate commercial revenue, it could allow Nano to validate that its technology works safely.
Which is better for investors today: Oklo or Nano?
Oklo has the stronger business case. Not only does it have major tech partners, but it also has a backlog of projects that can generate meaningful revenue. Even though it's still pre-revenue today, it'll likely turn on the spigot within the next two years, as the chart below shows.
Data by YCharts
That said, Nano Nuclear could provide more upside from here. Trading at $26 a share, Nano carries a market cap of about $1.4 billion -- a fraction of Oklo's $12.5 billion. While that's still richly valued for a pre-revenue company, it seems much more reasonable than Oklo's much steeper valuation.
