X-energy, a nuclear power startup developing small modular reactors, saw its shares jump 27% on its first day of trading on the Nasdaq on Thursday, April 24, following an upsized initial public offering that signalled robust appetite among investors for next-generation nuclear energy companies.
X-energy made a striking entrance to public markets on Thursday, with shares climbing 27% on its opening day of trading on the Nasdaq — a performance that underscored growing investor enthusiasm for advanced nuclear power technologies.
The company had upsized its IPO ahead of the listing, a move that typically reflects strong demand from institutional investors during the bookbuilding process. The decision to increase the size of the offering before trading began suggested that early interest exceeded initial expectations, and the first-day trading results appeared to validate that confidence.
X-energy is among a new generation of nuclear energy companies pursuing small modular reactor (SMR) technology, which proponents argue can be built faster, cheaper, and more safely than conventional large-scale nuclear plants. The company has been developing its Xe-100 reactor design, a high-temperature gas-cooled reactor that can generate up to 80 megawatts of electricity per unit.
The IPO comes at a moment of renewed interest in nuclear power across the United States and globally, driven by surging electricity demand from data centres, artificial intelligence infrastructure, and broader electrification trends. Major technology companies including Microsoft, Google, and Amazon have all announced agreements in recent years to source power from nuclear facilities, helping to rehabilitate the sector's commercial prospects after decades of stagnation.
X-energy has previously attracted backing from high-profile partners, including a collaboration with Dow, the chemical and materials company, to potentially deploy reactors at industrial facilities — a market segment that SMR developers have identified as particularly promising given the need for reliable, carbon-free process heat and electricity.
The company also received a $80 million award under the US Department of Energy's Advanced Reactor Demonstration Program, lending some government validation to its technology roadmap.
Despite the enthusiasm, the advanced nuclear sector faces significant challenges. No SMR design has yet been commercially deployed at scale in the United States, regulatory timelines remain lengthy, and construction costs for novel reactor designs are difficult to predict with confidence. Several SMR ventures in recent years have encountered delays and cost overruns.
Nevertheless, Thursday's market debut suggests that public investors are willing to place early bets on the sector, even amid those uncertainties.
Analysis
Why This Matters
- A strong IPO for a nuclear startup signals that public markets are now open to early-stage advanced nuclear companies, potentially unlocking a new funding pathway for the sector beyond government grants and private capital.
- Surging electricity demand from AI data centres has fundamentally changed the commercial calculus for nuclear power, giving companies like X-energy a credible near-term customer base.
- The listing will serve as a benchmark for other SMR developers considering public offerings, shaping how the broader sector is valued.
Background
Nuclear power fell out of commercial favour in the United States after the Three Mile Island accident in 1979, and enthusiasm waned further following the Fukushima disaster in 2011. For decades, high construction costs, regulatory complexity, and cheap natural gas made new nuclear projects economically unviable.
The landscape began shifting in the late 2010s and accelerated through the 2020s as climate concerns, energy security pressures, and the electricity demands of the digital economy converged. The US government invested heavily in next-generation designs through the Department of Energy's Advanced Reactor Demonstration Program, launched in 2020, which provided funding to companies including X-energy and TerraPower.
By 2023 and 2024, major technology companies began signing power purchase agreements with nuclear operators and developers, lending commercial credibility to the sector. This corporate demand has been a key catalyst for renewed investor interest heading into 2025 and 2026.
Key Perspectives
Nuclear energy proponents: Argue that SMRs represent a scalable, low-carbon baseload power source uniquely suited to meeting 24/7 electricity demand from data centres and industrial users, and that X-energy's IPO demonstrates the technology is approaching commercial viability.
Technology sector buyers: Companies like Microsoft and Amazon have made long-term bets on nuclear power to meet sustainability targets and secure reliable electricity, making them natural anchor customers for SMR developers — a dynamic that strengthens X-energy's commercial story.
Critics and sceptics: Point out that no SMR has yet been commercially operated in the US, that regulatory approval timelines are uncertain, and that construction costs for first-of-a-kind reactors are historically prone to significant overruns. Some analysts caution that first-day trading pops can reflect speculative enthusiasm rather than fundamental value.
What to Watch
- Progress toward NRC licensing approval for the Xe-100 reactor design, which remains a critical gating factor for commercial deployment.
- Whether X-energy announces binding power purchase agreements or letters of intent with industrial or technology sector customers in the months following the IPO.
- How other SMR developers — including TerraPower, Kairos Power, and NuScale — respond to the IPO's success and whether additional public listings follow in the sector.