ATI vs RS: How ATI Inc. and Reliance Compare (2026)

Same yardstick, side by side (as of July 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: RS 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. ATI and RS 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 ATI and RS 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.

ATI Inc. (ATI), formerly Allegheny Technologies, is a specialty materials and components producer focused on high-performance metals for demanding applications. Its core markets are aerospace and defense, where ATI supplies titanium, nickel-based superalloys, and other advanced alloys used in jet engines, airframes, and defense systems that must withstand extreme heat, stress, and corrosion. The company also serves medical, energy, electronics, and specialty industrial markets. ATI operates through two segments: High Performance Materials and Components (jet engine parts, forgings, and advanced alloys) and Advanced Alloys and Solutions (specialty rolled products and materials). The company has deliberately repositioned over the past several years away from lower-margin commodity stainless toward higher-value, harder-to-make aerospace and defense materials where it has technical differentiation and long qualification cycles that lock in customer relationships. Founded through the combination of specialty metals businesses and headquartered in Dallas, Texas, ATI is a cyclical industrial materials company whose results are tied closely to commercial aerospace production rates and defense spending.

Full ATI guide

Reliance, Inc. (NYSE: RS) is the largest metals service center operator in North America, a role it has held for well over a decade. Rather than making metal, Reliance buys it from mills and distributes over 100,000 products (carbon steel, stainless, aluminum, brass, copper, titanium and alloy steel) to more than 125,000 customers, often after value-added processing such as slitting, laser cutting and machining. Roughly half of its orders include some processing, which makes the business more of a just-in-time industrial supply-chain operator than a pure commodity reseller. The model is highly decentralized across a family of companies and diversified across end markets like nonresidential construction, aerospace, automotive, energy and general manufacturing.

Full RS guide

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

• ATI drivers: Commercial aerospace recovery and ramp; Mix shift to high-value materials.
• RS drivers: Scale and market-share gains; Value-added processing mix.

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: ATI is cyclical and concentrated in aerospace, so any slowdown in commercial aircraft production (for example, Boeing supply-chain or quality problems, or an air-travel downturn) hits demand directly. For RS, reliance is a cyclical business exposed to volatile steel, aluminum and specialty-metal prices, which can compress both revenue and gross margins when prices fall.

Pick ATI if you believe its drivers more; RS 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 ATI and RS guides.

ATI. ATI trades as a cyclical aerospace and defense materials supplier, with its multiple expanding when commercial aircraft build rates and defense demand are strong. The repositioning toward higher-value alloys has improved margins and earnings quality, but the valuation still reflects sensitivity to the aerospace cycle and raw-material and capacity-ramp risks rather than steady-state stability.

RS. Reliance grew FY2025 net sales about 3.3% to roughly $14.3 billion on record tons sold, then posted a strong Q1 2026 with net sales near $4.03 billion and non-GAAP diluted EPS of $5.16, above its guidance range. The stock trades around a low-20s trailing P/E and high-teens forward P/E, with an EV/EBITDA near 13. Its roughly 1.6% dividend yield sits on a 33-time-increased, decades-long payout record, and management has kept buybacks active.

Headline figures (approximate, early 2026): ATI shows revenue (ttm) ~$4.5 billion, operating margin ~low-double-digit percent (improving with mix), net income (ttm) ~$350-450 million, p/e (ttm) ~20-25x (cyclical); RS shows revenue (ttm) ~$14.8B, fy2025 net sales ~$14.3B, q1 2026 net sales ~$4.03B (up ~15.5% YoY), market cap ~$19-20B.

ATI and RS 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 ATI and RS exposure against your real portfolio. It is not an investment adviser.