CEG vs OKLO: How Constellation Energy and Oklo 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. CEG and OKLO 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 CEG and OKLO 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.

Constellation Energy (CEG) is the largest producer of carbon-free electricity in the United States, operating the country's biggest fleet of nuclear power plants alongside hydro, wind, and solar assets. Spun off from Exelon in 2022, it generates and sells power and provides energy services to commercial, industrial, government, and residential customers. Constellation's nuclear fleet produces large, steady volumes of around-the-clock, low-carbon electricity, which has become increasingly valuable as datacenters, electrification, and AI computing drive up demand for reliable clean power. The company has pursued long-term power-supply agreements with large energy buyers, including technology companies seeking carbon-free electricity for datacenters, and announced an agreement to acquire Calpine, a major natural-gas and geothermal generator, to broaden its generation mix. Headquartered in Baltimore, Maryland, Constellation benefits from federal clean-energy incentives, including production tax-credit support for existing nuclear plants.

Full CEG guide

Oklo (OKLO) is a US advanced-nuclear company developing small modular fast reactors, branded the Aurora powerhouse, intended to deliver clean baseload electricity from compact, factory-buildable units. Its model is to own and operate the plants and sell power under long-term agreements rather than just sell reactors, positioning it as a power provider for data centers, industrial users, and grid customers. Oklo also pursues recycling of used nuclear fuel as part of its long-term plan. The company is pre-revenue: it has no operating commercial reactors generating power yet, and its value rests on advancing reactor design, securing US Nuclear Regulatory Commission licensing, building a supply chain and fuel access, and converting a pipeline of customer interest into deployed, revenue-generating plants. Oklo became publicly traded through a SPAC merger and trades on the New York Stock Exchange. It is closely associated with the AI-driven surge in electricity demand and the broader nuclear revival, which makes it a high-profile but speculative early-stage holding.

Full OKLO guide

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

• CEG drivers: Datacenter and AI power demand; Nuclear fleet value and clean-energy support.
• OKLO drivers: AI-era electricity demand; Own-and-operate power model.

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: Constellation has merchant exposure, so its results depend partly on wholesale power and commodity prices, which can be volatile. For OKLO, oklo is pre-revenue with no operating commercial reactors, so it carries substantial execution risk: NRC licensing is rigorous and can take years, first-of-a-kind nuclear construction often runs over budget and behind schedule, and fuel supply (especially HALEU) is a real constraint.

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 CEG if you believe its drivers more; OKLO 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 CEG and OKLO guides.

CEG. Constellation trades at a higher multiple than most regulated utilities because investors price in growth from AI and datacenter power demand and the premium value of carbon-free baseload generation. That re-rating embeds optimism about long-term clean-power contracts; the multiple can compress if power-demand growth or policy support disappoints. All figures are approximate and move with power prices and the share price; verify current numbers before relying on them.

OKLO. Oklo cannot be valued on current earnings because it is pre-revenue; the market prices it on the size of the clean-power opportunity, its customer pipeline, and the probability of licensing, financing, and deploying reactors. Traditional P/E does not apply, and the stock is highly speculative and volatile, often moving with nuclear-theme and AI-power sentiment. All figures are approximate and should be verified against the latest filings.

Headline figures (approximate, early 2026): CEG shows revenue (ttm) ~$23-25 billion (approximate, verify), position Largest US producer of carbon-free electricity, fleet Largest US nuclear fleet plus hydro, wind, solar, p/e (ttm) ~25-30x or higher (approximate, verify); OKLO shows stage Pre-revenue advanced-nuclear developer (no operating commercial reactors), core product Aurora powerhouse small modular fast reactor, business model Own and operate plants, sell power under long-term agreements, revenue (ttm) Minimal to none from power sales (approximate, verify).

CEG and OKLO 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 CEG and OKLO exposure against your real portfolio. It is not an investment adviser.