SMR vs VST: How NuScale Power and Vistra Compare (2026)

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. SMR and VST share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined SMR and VST exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

NuScale Power (SMR) is a developer of small modular nuclear reactors (SMRs), aiming to commercialize compact, factory-built reactor modules as an alternative to large conventional nuclear plants. Its flagship design is a pressurized-water reactor module that can be deployed individually or in groups to scale capacity, and it is among the few SMR designs to receive design certification or approval from the US Nuclear Regulatory Commission, a notable regulatory milestone. The pitch for SMRs is safer, more standardized, lower-upfront-cost nuclear power that can provide carbon-free, always-on baseload electricity, including for data centers and industrial users with growing power needs. NuScale is majority-affiliated with Fluor, an engineering and construction firm, and works with utility and government partners. The company is early-stage and largely pre-revenue from operating plants: it has not yet brought a commercial SMR online, and an earlier flagship deployment project was cancelled, underscoring cost and timeline challenges. Headquartered in Portland, Oregon, NuScale is a speculative, long-horizon bet on whether small modular reactors achieve commercial scale and cost-competitiveness.

Full SMR guide

Vistra (VST) is one of the largest competitive power generators and retail electricity providers in the United States. It owns a diverse fleet of generation assets including natural gas, nuclear, coal, solar, and battery energy storage, and it sells electricity to homes and businesses through retail brands such as TXU Energy. Vistra is a major operator in the Texas (ERCOT) market and other competitive markets, and its acquisition of Energy Harbor added a sizable nuclear fleet, strengthening its position as a supplier of reliable, low-carbon baseload power. The company has become a prominent way to play surging electricity demand from data centers and artificial intelligence, since its nuclear and dispatchable generation can serve large, always-on loads. Vistra pays a dividend and has been returning capital through buybacks. Headquartered in Irving, Texas, VST is an independent power producer whose results are tied to power prices, demand growth, and its generation mix.

Full VST guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• SMR drivers: Regulatory progress and design certification; Demand for carbon-free baseload and data-center power.
• VST drivers: Data-center and AI power demand; Nuclear and dispatchable fleet.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: NuScale is early-stage and largely pre-revenue, with ongoing operating losses, so it depends on its cash and periodic capital raises that can dilute shareholders. For VST, as a competitive (unregulated) power generator, Vistra's earnings are sensitive to wholesale power prices, fuel costs, and weather, making results more volatile than a regulated utility with guaranteed returns.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick SMR if you believe its drivers more; VST if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the SMR and VST guides.

SMR. NuScale cannot be valued on earnings because it has little operating revenue and runs losses. The market prices it on the option value of small modular reactors reaching commercial deployment years out, so the stock is very volatile and moves on regulatory milestones, project announcements, government policy, and energy and AI-power sentiment. Figures are approximate and change frequently; verify current cash, burn rate, and share count, which dilution can move materially.

VST. Vistra is valued as an independent power producer whose earnings track wholesale power prices, demand, and its generation mix, so it is more cyclical than a regulated utility. The stock has re-rated alongside enthusiasm for AI and data-center electricity demand, which adds both upside and the risk of multiple compression if that demand underdelivers. All figures are approximate and should be verified against current filings.

Headline figures (approximate, early 2026): SMR shows revenue (ttm) ~minimal operating revenue (pre-commercial; verify), profitability Unprofitable; ongoing operating losses, cash burn ~tens of millions-plus per year (verify latest), cash position Supported by capital raises; varies (verify current); VST shows business Competitive power generation + retail electricity, generation mix Natural gas, nuclear, coal, solar, battery storage, revenue (ttm) ~$15-20 billion (verify), key markets Texas (ERCOT) and other competitive US markets.

SMR and VST are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined SMR and VST exposure against your real portfolio. It is not an investment adviser.