SMR vs XE: Which Is the Better Buy in 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 XE 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 XE 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

X-Energy, Inc. designs advanced small modular nuclear reactors and manufactures the fuel that powers them. Its flagship Xe-100 is a high-temperature gas-cooled reactor sized at roughly 80 megawatts of electric output (200 megawatts thermal), aimed at industrial sites and data centers, and its TRISO-X fuel business makes the coated-particle fuel the reactors run on. Founded in 2009 and headquartered in Rockville, Maryland, the company is developing its first Xe-100 plant at Dow's Seadrift site on the Texas Gulf Coast under the U.S. Department of Energy's Advanced Reactor Demonstration Program, and has offtake and partnership arrangements tied to Amazon, Dow, Centrica, Talen Energy, and utilities in Kentucky.

Full XE 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.
• XE drivers: AI and data-center power demand; Government backing and the Dow demonstration.

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 XE, x-Energy is pre-commercial, so it generates large losses and has no proven history of building and operating reactors at scale.

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; XE 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 XE 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.

XE. As of July 2026, X-Energy trades at a very high multiple of its modest revenue because the market is pricing future reactor deployments rather than current results. Q1 2026 revenue and grant income roughly doubled year over year to about $43 million, but losses remain large as the company invests in licensing, fuel facilities, and its first plant. The April 2026 IPO added roughly $1.1 billion of cash, funding operations toward its demonstration milestones.

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); XE shows share price ~$16.50, market cap ~$6.7B, revenue + grant income (ttm) ~$117M, 2025 revenue ~$94M.

SMR and XE 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 XE exposure against your real portfolio. It is not an investment adviser.