Global energy markets are undergoing a profound transformation, and nuclear power has re-emerged as a central pillar of the conversation. As governments and corporations search for reliable, carbon-free baseload energy to complement renewables, nuclear is increasingly seen as indispensable. Recent policy moves in the United States and United Kingdom underscore this trend: Washington has accelerated reactor approvals and uranium supply chain programs, while London has ramped up its commitments to small modular reactors (SMRs) and fuel security. This transatlantic cooperation is not only geopolitical—it’s financial, creating opportunities for investors across the nuclear spectrum.
The most speculative names are drawing the most headlines. Oklo (OKLO) has become emblematic of investor enthusiasm for SMRs, trading on expectations rather than current earnings. With virtually no revenue yet, negative EBITDA (~–$58M), and a sky-high price-to-book ratio near 20x, Oklo is essentially a bet on regulatory success, technological execution, and the ability to commercialize quickly. The company’s valuation—somewhere in the $15–20 billion range—is more reflective of future contracts and political support than present fundamentals. Yet with U.S.-U.K. cooperation advancing in areas like SMR design certification, Oklo has a strategic tailwind that could justify its lofty price if milestones are met.
A different picture emerges with NuScale Power (SMR), another SMR pioneer. NuScale’s shares have soared over 150% in the past year, boosted by regulatory approvals and momentum around pilot deployments. Its P/E ratios swing wildly negative or into the hundreds when excluding one-offs, and its P/B sits near 9x—still high, but lower than peers like Oklo. Here, too, the valuation is speculative, but investors are buying into the idea that SMRs can be exported globally, particularly as U.S. and U.K. regulators align to set international standards.
Then there are the utilities and engineering firms that anchor the sector with more tangible financials. Constellation Energy (CEG), with the largest nuclear fleet in the United States, trades at ~34x earnings and ~4x sales. These are rich multiples for a utility, but justified by nuclear’s newfound premium as a carbon-free, baseload solution. With annual revenues near $24 billion and healthy earnings growth, Constellation offers a more predictable cash-flow profile for investors who want exposure without the binary risk of SMR startups. Across the Atlantic, the U.K. government’s push to expand nuclear capacity by 2050 bodes well for utilities with operational fleets and financing strength, reinforcing the theme of Anglo-American nuclear cooperation.
Fluor (FLR) sits in the middle ground. As an engineering giant with a stake in NuScale and a role in large-scale nuclear construction, Fluor provides exposure to the build-out side of the cycle. Its revenues (~$4B per quarter) and market cap (~$6B) anchor it as an established player, but profitability has been under pressure from project cost overruns and delays. While not a pure nuclear stock, Fluor’s fortunes will rise if SMR and reactor projects accelerate on both sides of the Atlantic.
Other names add nuance to the picture. Nano Nuclear Energy (NNE), like Oklo, is pre-revenue and trades mostly on speculative momentum. US Nuclear Corp (UCLE), at the microcap end of the spectrum, has real operations but remains tiny relative to the sector. Meanwhile, uranium miners—essential suppliers to this revival—are seeing demand spike as U.S. and U.K. governments seek to diversify away from Russian and Kazakh uranium. This tightening supply chain is a quiet but powerful driver of valuations across the sector.
The narrative is reinforced by policy. In May 2025, Washington and London announced expanded cooperation on SMR licensing, uranium enrichment, and supply chain resilience, designed not only to advance domestic projects but also to establish Western leadership in nuclear exports. For investors, this is more than symbolism: aligned standards reduce regulatory risk, secure uranium flows protect input costs, and joint funding initiatives accelerate commercialization.
The investment thesis for nuclear stocks, therefore, splits along two lines. Established players like Constellation and Fluor offer relative stability and cash flow, priced at premiums due to nuclear’s strategic importance. Speculative innovators like Oklo and NuScale offer high-risk, high-reward exposure to next-generation designs, with valuations more a reflection of geopolitical momentum than balance-sheet fundamentals. Both groups are riding the same macro wave: nuclear power’s resurgence as a cornerstone of clean, secure, and cooperative transatlantic energy policy.
Analyst Note: Comparing Valuations in the Nuclear / SMR Space
Across the nuclear sector, there is a spectrum of risk and expectation. Some firms are high-risk, pre-revenue, building technologies and regulatory approvals; others are more stable, with existing assets and predictable cash flow. In addition, in the UK, government policy is playing a large role in shaping what will be built, by whom, and under what financial models. Understanding valuation requires putting together the metrics (P/E, P/B, market cap, revenue) with policy tailwinds and regulatory risk.
Oklo (OKLO, U.S.): Oklo is a pure “optionality” play. It has almost no revenue, negative earnings across the board (operating income, net income, EBITDA), no meaningful P/E because earnings are negative. Its current P/B (price to book) is extremely high (around 25-30×, depending on book value used). Its market cap / enterprise value have been reported between US$14-20 billion. Every metric shows this is forward-looking, speculative. Investors are paying for promises: licensing, regulatory approvals, SMR deployment, possibly power contracts. The downside is large (if things go wrong), the upside depends on execution over multiple years.
Rolls-Royce SMR (UK): Though not a public pure SMR “stock” in the same way, Rolls-Royce SMR represents what government-backed UK policy is trying to build. The UK government selected Rolls-Royce SMR as preferred bidder for its SMR programme, pledging £2.5 billion over 4 years. The design is expected to produce ~470 MWe per SMR, with ~3 units initially. Build cost estimates are between about £1.8-£3.0 billion per unit depending on series and scale. That gives implied cost per MW, lead times, and capital intensity that inform what returns might have to be to justify investment.
Other U.K. / British-related firms (examples): MoltexFLEX (private) developing molten salt SMRs; Rolls-Royce SMR’s selection implies subsidies, government support, and political backing. Those reduce risk but also constrain upside (returns will be affected by regulatory returns, cost overruns, public scrutiny). UK is simplifying permitting and expanding sites allowed, which increases addressable opportunity.
Conclusion & Implications
Putting this all together, the following emerges: speculative SMR / startup names like Oklo are priced for very high growth and success. Their valuation multiples reflect zero current revenues but high expectations—and correspondingly, significant risk. Established firms, or government-driven SMR programmes like the UK’s, are moving more slowly, but with more structural support, lower risk, and likely more modest (but steadier) returns. Governments in the U.S. and UK are increasingly cooperating: sharing regulatory standards, securing uranium supply chains, signing SMR deals, giving grants. That cooperation helps reduce certain risks (e.g. licensing uncertainty, supply chain bottlenecks), which improves the baseline for valuations across the sector.
For an investor considering entering this space, your return will depend heavily on choosing where along this risk spectrum you want to be: do you want high upside (and are you prepared for high risk), or more moderate but safer returns backed by policy and existing infrastructure? If you like, I can pull together full comparable metrics for a wider set (say 8-10 names) including uranium miners, reactor operators, SMR firms globally, so you can see where value seems under-appreciated vs where hype may be overdone.
| Name | Market Cap / EV* | Revenue / EBIT / EBITDA Snapshot | P/E (TTM or Forward) | P/B or Other Multiple | Key Notes / Risk Factors |
|---|---|---|---|---|---|
| Oklo (OKLO, U.S.) | ~$14–20B market cap; EV similar (~$19–20B) | Revenue ≈ 0; EBIT/EBITDA strongly negative (~–$50–70M) | N/A (negative earnings) | P/B ~25–30× | Pure SMR speculative play; high execution, regulatory, funding risk; large upside if deployments succeed. |
| NuScale Power (SMR, U.S.) | Mid-single-digit $B market cap (varies); EV similar | Low revenue; margins negative | Negative or very high when excluding one-offs | P/B ~9× (approx.) | First-mover SMR approvals; needs financing, customers, and timely build-out to justify valuation. |
| Constellation Energy (CEG, U.S.) | Large-cap utility; EV tens of $B | Annual revenue ~$23–25B; positive EBIT/EBITDA; growing EPS | ~33–34× (utility-premium range) | P/S ~4×; P/B ~7.5× | Largest U.S. nuclear fleet; more stable cash flows; exposure to power price and regulatory dynamics. |
| Fluor (FLR, U.S.) | EV ~$5–6B | ~$4B quarterly revenue; profitability pressured by project cost growth | Positive (varies with adjustments) | Traditional EPC multiples | EPC lever on nuclear/SMR build-out; backlog quality and project execution drive margins. |
| Nano Nuclear Energy (NNE, U.S.) | Small/mid $B market cap (varies); EV similar | Pre-revenue; negative EBIT/EBITDA | N/A | High P/B (book small) | Early-stage microreactor/SMR concept; highly speculative with long timelines. |
| US Nuclear Corp (UCLE, U.S.) | Microcap | Modest revenue; negative earnings | N/A | P/S <1× (varies) | Tiny scale; niche products; high volatility and liquidity risk. |
| Rolls-Royce SMR / UK SMR Programme (UK) | Gov’t-backed within Rolls-Royce ecosystem; UK pledged ~£2.5B | Unit capex ~£1.8–£3.0B per 470 MWe SMR (est.) | N/A (programme economics via RAB/CFD-like models) | Cost per MW, regulated returns | UK policy tailwind; build and licensing risk; outcomes shaped by regulated frameworks and cost control. |
| “Utilities / Established Operators” (peer set) | Large EVs; balance-sheet intensive | Meaningful revenue; positive EBIT/EBITDA | ~20–35× typical for growth-oriented nuclear utilities | Moderate P/B, P/S varies | Lower risk than startups; exposed to fuel supply, maintenance, regulatory and market power prices. |
| *EV = Enterprise Value. Figures are approximate and subject to change with market prices and filings. | |||||
