CMI vs GNRC: 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. CMI and GNRC 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 CMI and GNRC 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.

Cummins Inc. is one of the world's largest independent makers of diesel and natural gas engines, and it operates across five segments: Engine, Components, Distribution, Power Systems, and Accelera (its low-carbon and electrification arm). Its products power heavy- and medium-duty trucks, buses, construction and mining equipment, and standby and prime power generators, and it runs a large aftermarket parts and service network. The Distribution segment is the largest by revenue, while Power Systems has been the fastest-growing thanks to demand for backup power at data centers.

Full CMI guide

Generac Holdings is the leading US manufacturer of backup power systems, best known for automatic home standby generators that switch on when the grid goes down. The company also builds commercial and industrial (C&I) generators, mobile power and lighting equipment, portable generators, and a growing line of residential energy technology such as battery storage, solar inverters, and grid-services software. As of March 2026 Generac reorganized its reporting into two segments, Residential and Commercial & Industrial, reflecting how management now runs a unified home-energy business alongside a consolidated global C&I operation. Demand for its core product is driven by grid reliability concerns, aging electrical infrastructure, and more frequent severe weather, which makes power-outage activity a major swing factor in results.

Full GNRC guide

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

• CMI drivers: Data center backup power; North American truck cycle.
• GNRC drivers: Data center and C&I backup power; Home standby generators and grid reliability.

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: Cummins is exposed to the industrial and freight cycle, so a downturn in truck demand or construction spending can cut engine volumes and margins quickly. For GNRC, generac's residential business is cyclical and weather-driven: a year with low power-outage activity, as in 2025, can depress home standby demand and pressure results, while the timing and severity of storm seasons are outside the company's control.

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 CMI if you believe its drivers more; GNRC 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 CMI and GNRC guides.

CMI. Cummins trades at a premium to its historical multiple after a large 2025-2026 run tied to data center power demand. The forward P/E near 23x sits well below the trailing figure, reflecting expected earnings growth as guidance was raised. The dividend is modest in yield but backed by a long record of annual increases.

GNRC. Generac's FY2025 net income of about $160 million fell roughly 51% from the prior year, but much of that drop reflects a one-time legal settlement provision of about $104.5 million rather than a collapse in the underlying business. The high trailing P/E near 77x is distorted by that charge, which is why the forward P/E in the mid-20s is a cleaner read on how the market values expected earnings. The premium multiple reflects optimism about data center growth and a recovery in outage-driven residential demand.

Headline figures (approximate, JUNE 2026): CMI shows revenue (fy2025) ~$33.7B, revenue (q1 2026) ~$8.4B, up ~3% YoY, net income (fy2025) ~$2.8B, market cap ~$96B; GNRC shows revenue (fy2025) ~$4.2 billion, net income (fy2025) ~$160 million (cut by a ~$104M legal settlement), revenue (q1 2026) ~$1.06 billion (up ~12% year over year), adjusted eps (q1 2026) ~$1.80.

CMI and GNRC 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 CMI and GNRC exposure against your real portfolio. It is not an investment adviser.