How to Invest in Nuclear and SMR

How do SMRs differ from traditional reactors?

Small modular reactors, the SMRs at the heart of this theme, differ from traditional plants mainly in size and how they are built. A conventional reactor is a massive, one-off project producing roughly 1,000 megawatts, built on site over many years with significant cost and schedule risk. An SMR is designed to be much smaller, often factory-fabricated in standardized modules and shipped to the site, with the goal of cheaper, faster, more predictable deployment. OKLO and SMR (NuScale) are developing two different SMR approaches, and BWXT manufactures reactor components and fuel for advanced designs.

That manufacturing-led model is the core promise of the nuclear and SMR theme: if reactors can be standardized and built in a factory, the historical cost overruns that hurt large nuclear projects could shrink. The catch, and the reason the SMR side of the theme carries real risk, is that this is still being proven. As of 2026 the SMR developers in the nuclear and SMR theme are largely pre-revenue, so they are bets on commercialization rather than on current earnings.

Why is data center demand reviving nuclear power?

Data centers, especially AI training campuses, need enormous amounts of electricity that is available 24 hours a day, and nuclear is one of the few sources that delivers firm, carbon-free power at that scale. That is the demand catalyst behind the nuclear and SMR theme. Hyperscalers have signed power agreements with nuclear operators, and some have backed SMR developers directly, because matching round-the-clock AI compute with intermittent wind and solar alone is difficult. This has turned existing reactors from stranded assets into prized, contracted capacity.

This demand pulls the two halves of the nuclear and SMR theme together. Operators like CEG and VST that own existing reactors benefit immediately, because their firm output can be contracted to data centers at attractive prices today. SMR developers like OKLO and SMR benefit on a longer horizon, as a potential way to add new firm capacity without the cost profile of a giant conventional plant. GEV supplies the turbines and grid equipment, and CCJ supplies the uranium, so the demand surge flows across the whole nuclear and SMR supply chain.

What is the nuclear fuel and engineering supply chain?

Behind every reactor in the nuclear and SMR theme is a fuel and engineering chain. It starts with uranium mining, where CCJ (Cameco) is one of the largest Western producers, then moves through conversion and enrichment into reactor-grade fuel. BWXT manufactures nuclear components and fuel, including for naval reactors and advanced designs, giving it a specialized engineering moat. GEV (GE Vernova) supplies large turbines and grid equipment and is developing its own SMR design, bridging the operator and developer sides of the theme.

The nuclear and SMR theme spans this chain because a reactor is only as investable as the fuel and engineering behind it. A new build needs uranium supply (CCJ), licensed designs and components (BWXT, OKLO, SMR), turbines and grid interconnection (GEV), and an operator to run it (CEG, VST). Grouping these together is what lets the nuclear and SMR theme capture the full thesis rather than a single, isolated link.

What gets a stock into the Nuclear and SMR theme?

Revenue or development exposure to nuclear power: operators of existing reactors, small modular reactor developers, uranium miners and fuel suppliers, and reactor component, turbine, and engineering firms.

What stocks are in the Nuclear and SMR theme?

Every public name that fits the Nuclear and SMR thesis, with the rationale for inclusion. Click any ticker for the full stock guide. The basket above starts equal-weighted; you set your own target weights inside Walnut.

How to invest in Nuclear and SMR

There are a few ways to get exposure to the nuclear and SMR theme, and Walnut is not an investment adviser, so this is descriptive. The most concentrated path is buying individual stocks that fit the thesis. You can lean toward cash-generating exposure with operators like CEG and VST and uranium supplier CCJ, add the engineering and turbine suppliers BWXT and GEV, or take more speculative exposure through the SMR developers OKLO and SMR. The key distinction within the nuclear and SMR theme is that the operators earn real money today while the SMR developers are largely pre-revenue, so the names you choose set very different risk profiles. The passive route is limited: XLE (energy sector) holds only modest nuclear-related exposure, and there is no pure-play nuclear or SMR ETF in Walnut's valid proxy set as of early 2026, so passive exposure is heavily diluted.

The alternative is building a dedicated nuclear and SMR basket in Walnut. You describe the thesis to Walnut's AI assistant, for instance nuclear and SMR spanning existing-reactor operators, SMR developers, fuel, and engineering, and the assistant proposes constituents and starting weights drawn from names like CEG, VST, CCJ, OKLO, SMR, BWXT, and GEV, with the rationale for each. You can deliberately balance the steady operators against the speculative SMR names, review and adjust every weight, and fund the basket through your own connected broker. You approve every order before it is placed; Walnut never trades for you. The nuclear and SMR basket then tracks as a single performance line.

Which ETFs cover Nuclear and SMR?

If you want the theme as a single ticker rather than as a basket, these are the ETFs people most commonly use. Each has trade-offs (concentration, expense ratio, sector overlap) covered in the individual ETF guides.

The bottom line on Nuclear and SMR

Nuclear and SMR splits cleanly into two risk profiles: cash-generating operators of existing reactors (CEG, VST) and uranium suppliers (CCJ) on one side, and pre-revenue SMR developers (OKLO, SMR) plus engineering and turbine suppliers (BWXT, GEV) on the other. Data-center demand for firm clean power is the catalyst tying them together. The theme fits a portfolio as a satellite tilt, and a focused basket lets you balance the operators against the speculative SMR names better than XLE, which barely touches nuclear.

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