The SMR IPO landscape: Capital is flowing. The question is: whose?

Three years ago, a small modular reactor developer announcing a billion-dollar public listing would have been treated as a curiosity, perhaps a novelty, possibly a red flag. Today it is becoming routine.

The SMR sector has entered one of the most concentrated periods of capital-market activity in nuclear-energy history. Companies that were, until recently, dependent on government grants, strategic investors, and patient private capital are now accessing public equity markets at scale. The volume and pace of listings in 2025 and 2026 are without precedent in the sector’s modern history.

On balance, this is a significant positive for nuclear energy. Public markets provide depth, liquidity, and visibility that private capital cannot replicate at scale. Indeed, they force discipline on governance, disclosure, and the rigour of financial projections, and signal something the nuclear sector has struggled to demonstrate for two decades: that institutional investors believe in the long-term commercial case.

But a pattern is emerging within the IPO wave that deserves more careful scrutiny than it has received. When European SMR developers seek capital, they increasingly do so in the United States. The implication is precise: European nuclear champions, built to serve European energy security, are being owned and priced by American capital markets.

That is not inherently a problem. It is, however, a tension the industry and European policymakers should name clearly.

What the IPO wave actually looks like

The SMR capital markets story began in earnest with NuScale Power, which listed on the New York Stock Exchange (NYSE: SMR) via a SPAC business combination, becoming the first pure-play SMR company to trade publicly. NuScale holds a distinction that matters: the only SMR design currently certified by the US NRC. That regulatory milestone makes it the closest analogue, in Western markets, to a company with a deployable product.

NANO Nuclear Energy (NASDAQ: NNE) was among the earliest movers, completing a traditional IPO in May 2024, raising $10.25 million at $4 per share, and becoming the first micro-nuclear reactor company to list on Nasdaq. Its designs, ZEUS and ODIN, are sub-10 MWe microreactors targeting remote and off-grid applications. Modest in scale at listing, NANO established that public markets would accept pre-revenue nuclear at the smallest end of the reactor spectrum.

Oklo (NYSE: OKLO) followed, also via a business combination. It focuses on sodium fast microreactors, targeting industrial and data centre customers directly, a go-to-market model that has attracted significant attention amid AI’s surging energy demand. As of late 2025, Oklo reached a market capitalisation of approximately $18 billion.

In April 2026, X-Energy (NASDAQ: XE) priced its IPO at $23 per share, raising capital to commercialise its high-temperature gas reactor technology. Amazon is a cornerstone strategic backer, and the relationship has become a significant commercial validator in the market’s eyes. X-Energy’s HTGR design offers both power generation and high-temperature process heat, making it relevant beyond the electricity sector.

Then came Fermi America, co-founded by former US Energy Secretary Rick Perry, which raised $682 million in its IPO and launched with a market capitalisation of approximately $12.2 billion. Fermi is not, however, an SMR vendor in the mould of Oklo or X-Energy. It is a project developer and integrator; its primary plan is to build four Westinghouse AP1000 reactors on an 11-gigawatt campus near Amarillo, Texas, through its “Project Matador” programme. It has signed a FEED contract with South Korea’s Hyundai Engineering & Construction and a forging agreement with Doosan Enerbility for reactor pressure vessels and steam generators. Fermi also holds an MoU with Doosan covering future SMR technology, but the flagship commitment is conventional large-scale nuclear. The company’s stock market debut was fuelled by AI data centre power narratives; the underlying business plan is closer to that of a nuclear project developer than a technology licensing company.

These headline listings represent only part of the picture. A secondary tier of companies has also entered or is entering public markets, extending the wave well beyond the names that dominate financial press coverage.

Terrestrial Energy (NASDAQ: IMSR) followed via a SPAC merger with HCM II Acquisition Corp., completing its business combination in late October 2025 and raising approximately $292 million in gross proceeds. The Canadian company is developing the Integral Molten Salt Reactor, a Generation IV design targeting industrial heat and power generation. Its listing made it the world’s first publicly traded molten salt reactor developer.

Deep Fission (NASDAQ: FISN) filed its prospectus in June 2026, raising $40 million at $16 per share. Its Gravity Reactor takes a novel approach: a pressurised water reactor installed in a deep vertical borehole about one mile underground, using hydrostatic water pressure instead of conventional pressure containment. The company is pre-revenue and early-stage, with an initial pilot configuration targeting up to 8 MWe.

Hadron Energy got listed via a SPAC merger with GigCapital7 under the planned ticker HDRN. The company reset its valuation from $1.2 billion to $600 million in April 2026, deliberately adjusting to public market conditions after the broader repricing of advanced nuclear equity. Hadron is developing the Halo micro-modular reactor, a light-water design targeting 10 MWe and 35 MW of thermal output, with NRC design-certification applications planned for the fourth quarter of 2026.

Finally, and most significant from a European perspective: Newcleo recently got listed on Nasdaq via a merger with NewHold Investment Corp III, at a pre-money valuation of $2.4 billion. Newcleo, a Franco-British company founded in Turin, is developing a lead-cooled fast reactor and has technology and commercial ambitions spanning France, the UK, and wider European markets. It would be the first originally European advanced nuclear company to access US public equity markets at scale. Its auditor has raised going-concern questions, citing recurring losses of about €140 million in 2025, underscoring the financial pressure that makes US capital so attractive compared with European alternatives.

The listing that received the least attention, but may prove the most strategically significant, came on October 2, 2026. Steady Energy, a Finnish SMR developer focused on low-carbon district heating, debuted on Nasdaq Helsinki First North. Its IPO was small by the standards of the wave: €5 million. It was oversubscribed. Shares fell roughly 6% on their first day of trading. On its own, the numbers are modest. In context, they mark something new: a European SMR company tapping public equity markets on a European exchange. The Nasdaq Helsinki First North is usually seen as the first step before moving onto Nasdaq.

Then, on September 16, 2026, Holtec International, positioned as one of the year’s largest nuclear IPOs, targeting a valuation above $10 billion and seeking to raise $900 million, officially cancelled its public listing. Holtec’s CEO described the environment as “a perfect storm,” citing the market’s sharp turn against the AI data centre economy in the weeks before the planned debut. The registration remains on file. Holtec expects to attempt the listing again within three to six months.

The performance reality

The companies that have listed face a common challenge: public markets are pricing them as long-duration technology bets, and in 2026, patient capital has become expensive.

NuScale’s share price has declined approximately 48% Year-To-Date. Oklo has fallen around 51% from its highs. X-Energy, which priced at $23 per share in April, traded near $14 by mid-year, down roughly 40% from its IPO price within months of listing.

The explanation is quite simple. Every publicly traded SMR vendor operating today is pre-commercial. None has a commissioned reactor generating electricity at commercial scale – even Oklo with its Groves reactor that reached criticality within the DOE Reactor Pilot Program is still a long way from commercial operations. None has a signed, binding power purchase agreement that would commit a customer to long-term offtake and clear the path to construction financing. The deals in the backlog are, in the main, letters of intent, memoranda of understanding, and framework agreements – commitments in principle, not capital.

Public markets, which were willing to overlook this in 2024 and early 2025 when AI demand narratives were at their most expansive, have become more discriminating. The correction in SMR equity prices in 2026 reflects a repricing of timeline risk, not a change in the fundamentals. Bank of America’s assessment that nuclear energy represents a $10 trillion opportunity over the next 25 years remains unchanged. McKinsey’s projection that the world will deploy $7 trillion to build AI data centres by 2030 remains unchanged. What has changed is the market’s patience with companies that have yet to translate that demand into binding commercial commitments.

The single most consequential catalyst the sector is waiting for is a signed, bankable power purchase agreement from a creditworthy counterparty. NuScale is in active negotiations with the Tennessee Valley Authority on a potential PPA for a 6 GW facility, which would represent the largest SMR deployment in the world by a considerable margin. If that agreement is signed before the end of 2026, the market’s assessment of SMR equity will change materially.

The question that Europe has not answered

The US listings dominate both capital raised and media attention. But the most strategically interesting development in the SMR IPO landscape is not what is happening in New York or on the Nasdaq. It is what is happening, and what is not happening, in Europe.

Steady Energy’s Helsinki debut is significant precisely because it is an exception. Europe is home to a meaningful cluster of advanced nuclear developers with genuine technical depth. Several have ambitions that exceed what European public equity markets can currently finance, and the capital logic is pushing them toward New York. Newcleo’s decision to pursue a Nasdaq listing rather than a European exchange best illustrates this dynamic. A Franco-British company, founded in Turin, with regulatory ambitions in France and the UK, is going to Wall Street because that is where the equity is.

When European SMR developers require equity capital beyond what domestic investors can provide, the default path leads to US markets: NASDAQ, NYSE, or the SPAC structures that precede them. The rationale is straightforward. US markets are deeper, more liquid, and more experienced with high-growth, pre-revenue technology companies. US institutional investors have developed frameworks for valuing pre-commercial nuclear assets that European institutional capital, broadly speaking, has not yet built.

The practical consequence is this: a European SMR company that lists in the United States acquires ownership structured around US institutional priorities, US activist shareholder norms, US reporting cycles, and, ultimately, a valuation driven by US market sentiment. In a sector where political and regulatory decisions will be made in Brussels, Paris, Warsaw, and Helsinki, that misalignment between ownership and operating environment carries long-term implications.

This is not a new dynamic. European technology champions have been listed in the United States for decades, and the debate over European capital market depth is long-standing. But nuclear energy is not a standard technology sector. It is a sector where the intersection of energy security, defence considerations, and regulatory sovereignty makes ownership more contentious than in most industries.

The European Investment Bank’s €40 million loan to Steady Energy in September 2026 is one response to this challenge, and an encouraging one. EIB has indicated that further loans to SMR developers are expected. The European Innovation Fund, national development banks, and sovereign wealth vehicles are increasingly present as potential co-investors. But debt is not equity. And the equity gap that drives European SMR companies toward US markets remains.

What this means for the market

The IPO wave does not resolve the fundamental challenge facing every SMR developer: the valley between a certified design and a commissioned plant is wide, expensive, and full of execution risks. Capital markets provide the fuel, but they cannot build the reactors. The next 18 to 24 months will be defined not by IPO filings, but by whether the industry can produce its first bankable, binding customer commitments in Western markets.

Three things are clear from the current landscape.

First, the market is willing to fund pre-commercial nuclear at scale, but not indefinitely without evidence of commercial traction. The repricing of 2026 is a signal, not a sentence. The sector retains substantial institutional support. What it needs are milestones, PPAs, construction permits, first-of-a-kind project financial closes that transform the narrative from promise to proof.

Second, the US remains the dominant venue for SMR capital formation, and that dominance will likely persist as long as European equity markets lack the depth and risk appetite to compete. Holtec’s cancelled IPO demonstrates that even the US market has limits in adverse conditions, but it also demonstrates that the intention to list is undiminished. The pipeline of planned nuclear public listings remains substantial.

Third, and perhaps most importantly for European stakeholders: the question of where European SMR capital is raised is also a question about where European nuclear is governed. A Finnish heating company whose shareholder base is predominantly American is not the same strategic asset as a Finnish heating company financed by Finnish or European capital. That distinction will matter when technology licensing decisions are made, when manufacturing partnerships are structured, and when the geopolitics of the energy transition inevitably produce pressure.

The IPO wave is a genuinely good development for nuclear energy. It is bringing capital, discipline, and visibility to a sector that needs all three. But for Europe specifically, the question of how to build the capital infrastructure that keeps European nuclear champions in European hands remains open, and is becoming more urgent as the first wave of SMR listings reshapes the industry’s ownership map.

Capital is flowing into the SMR sector at a pace not seen in a generation. The conversation now needs to be about whose capital, on whose terms, and the long-term implications for the countries that have decided nuclear energy is part of their future.