ST vs STM: 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.

Reading it: ST 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. ST and STM 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 ST and STM 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.

Sensata Technologies Holding plc is a global industrial technology company that designs and makes sensors, high-voltage protection, and electrical components used mainly in automotive, heavy-vehicle and off-road, industrial, and aerospace applications. It reports in two segments: Performance Sensing, which supplies sensors and high-voltage solutions for cars and heavy vehicles (things like tire-pressure monitoring, thermal management, electrical protection, and powertrain sensing) and made up roughly 70% of sales in fiscal 2024, and Sensing Solutions, which sells application-specific pressure, temperature, and position sensors plus motor protectors, high-voltage contactors, relays, and battery-management products into industrial and other markets. Because most of its revenue is tied to vehicle production, Sensata's results track global light-vehicle build rates and its ability to win content on new platforms far more than any one product line.

Full ST guide

STMicroelectronics designs and manufactures a broad range of semiconductors, including analog chips, power and discrete devices (notably silicon carbide, where it holds the largest global share at roughly a third of the market), microcontrollers, MEMS sensors, and RF products. Its customers are concentrated in automotive (electrification, ADAS, body and safety electronics) and industrial (factory automation, power conversion, energy), with a more cyclical consumer and personal-electronics business layered on top. Unlike fabless designers, ST owns its fabs, which makes it capital-intensive and highly sensitive to factory utilization, a dynamic that has weighed heavily on margins during the recent downturn.

Full STM guide

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

• ST drivers: Margin recovery and cost execution; Electrification content per vehicle.
• STM drivers: Silicon carbide and automotive electrification; Cyclical recovery off the trough.

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: The dominant risk is automotive cyclicality: with most revenue tied to vehicle production, a slowdown in global light-vehicle builds can pressure volumes, and prolonged softness tends to show up later as program churn and factory under-absorption. For STM, sTM is deeply cyclical and capital-intensive, so weak factory utilization can compress margins sharply, as it did in 2025 when operating margin fell near breakeven.

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 ST if you believe its drivers more; STM 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 ST and STM guides.

ST. Figures are approximate and tied to the asOf date; verify live numbers before acting. The trailing P/E near triple digits is misleading because it divides the price by earnings that were depressed by large 2024 and 2025 goodwill and restructuring charges, so the forward P/E around 12x is the more useful gauge. For a cyclical auto supplier, the valuation ultimately hinges on where vehicle production and margins sit in the cycle rather than on a single multiple.

STM. STM's valuation looks expensive on forward earnings largely because profits are depressed at the bottom of the cycle, not because the business is structurally rich. Revenue troughed near $3.1 billion in Q1 2026 with gross margin around 33.8%, well below the 44 to 46% level management targets in its longer-term model. The multiple therefore embeds an expectation that margins and earnings recover meaningfully over the next couple of years.

Headline figures (approximate, July 2026): ST shows revenue (ttm) ~$3.7 billion (Q1 2026 was ~$934.8 million, up ~2.6% year over year), adjusted eps (q1 2026) ~$0.86 (GAAP EPS ~$0.59), net income (q1 2026) ~$87 million attributable to common shareholders, market cap ~$7 billion (mid-cap); STM shows revenue (ttm) ~$12B, fy2025 revenue ~$11.8B (down ~11%), q1 2026 revenue ~$3.1B (up ~23% YoY), q1 2026 gross margin ~33.8%.

ST and STM 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 ST and STM exposure against your real portfolio. It is not an investment adviser.