CEG vs CIG: How Constellation Energy and Cemig 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.

Reading it: CIG is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.

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 CIG 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 CIG 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

Cemig, incorporated in 1952 and headquartered in Belo Horizonte, is one of Brazil's largest integrated electric utilities and reports across six segments: Generation, Transmission, Trading, Distribution, Gas and Investees. As of December 31, 2025 it operated ~32 hydroelectric plants totaling ~4,434 MW, ~2 wind farms at ~71 MW and ~12 photovoltaic stations at ~169 MW, alongside ~365,577 miles of distribution lines and ~4,865 miles of transmission lines. Cemig D, the distribution arm, is the earnings anchor and serves the great majority of municipalities in Minas Gerais, Brazil's fourth-largest state economy. Gas distribution runs through Gasmig, and the trading arm sells into Brazil's expanding free market (mercado livre), where large and now mid-sized consumers choose their own supplier.

Full CIG 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.
• CIG drivers: A ~R$44 billion capex plan through 2028 that grows the regulated asset base; Distribution tariffs and loss control.

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 CIG, currency is the first-order risk: every real of earnings converts to fewer dollars when the real weakens, and the ADS price and dividend both absorb that directly.

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; CIG 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 CIG 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.

CIG. Cemig reports in Brazilian reais, so the dollar figures above are conversions and move with the exchange rate on their own. Full-year 2025 revenue was ~R$42.75 billion, up ~7.4%, and the 52-week ADS range of ~$1.88 to ~$2.76 shows how much the currency and the political narrative swing a stock whose underlying revenue is regulated. The next scheduled report is August 13, 2026.

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); CIG shows share price (ads) ~$2.10 (August 7, 2026), market cap ~$7.1 billion, revenue (ttm) ~$8.3 billion (~R$44 billion), net income (ttm) ~$927 million, down ~31% year over year.

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