A new U.S.-Canada trade war, marked by tens of billions in reciprocal tariffs, has triggered significant market volatility for critical metals and materials. While initial stock surges in sectors like steel quickly dissipated, the long-term impact is complicated by deeply integrated supply chains, particularly in the automotive industry, where products repeatedly cross borders.
Experts warn that temporary market gains mask the true challenge of these tariffs, forcing companies to undertake costly and time-consuming reallocations of their supply chains, with consequences that will permanently alter the economic landscape beyond 2025.
A new trade war has erupted between the United States and Canada, the U.S.'s second-biggest trading partner after Mexico, sending shockwaves through the critical metals sector and raising significant questions about economic volatility. Companies, economists, and investors are now deep into forecasting the widespread impacts on corporate balance sheets and stock prices.

Carlos Osorio | Reuters
The U.S. initiated the conflict by imposing 50% tariffs on approximately $20 billion worth of Canadian imports. Canada swiftly retaliated, announcing its own $20 billion in counter-tariffs, ranging from 15% to 50%, set to take effect on September 8. These measures target over 700 U.S. goods, mirroring the U.S. tariffs on Canadian wine, cement, and hockey sticks, and encompassing a broad range of U.S. dairy, seafood, appliances, wood and paper products, and apparel imports into Canada.
Initially, the market saw an immediate surge in metals and materials stocks following the breakdown of U.S.-Canada trade talks. Companies like Nucor (NUE), Steel Dynamics (STLD), Cleveland-Cliffs (CLF), and Century Aluminum (CENX) all rallied on Monday, recovering from declines the previous week that were driven by hopes of lower tariffs. The VanEck Steel ETF (SLX) jumped 1.6% on that Monday, while the State Street Materials Select Sector SPDR (XLB) hit an intraday all-time high, surpassing its February record, as metals producers soared.
However, this tariff-driven rally proved short-lived. By the end of the five-day trading week, XLB had fallen into negative territory, and SLX was nearly flat. Despite this recent fizzle, both ETFs have recorded substantial year-to-date gains in 2026, with SLX up over 28% and XLB more than 18%, both outperforming the S&P 500 as of August 28, according to Morningstar data.
Atsi Sheth, Chief Credit Officer at Moody's Ratings, emphasized the prevailing uncertainty. "Expect much more of this uncertainty for some time to come," Sheth stated, highlighting the challenge of navigating these new trade barriers.
The intricate web of global supply chains makes determining winners and losers in a trade war incredibly complex. The automotive sector, for instance, faces particular challenges due to its highly integrated nature, with parts frequently crossing the U.S.-Canada border multiple times during vehicle production. "For the auto sector, our view is that the sector is so integrated that the tariffs just don't impact the country you are tariffing but your own country," Sheth noted, adding that in the U.S.-Canada automobile manufacturing ecosystem, "the auto sector, there are no winners." U.S. steel companies, however, might gain a slight edge due to the larger domestic market.
"The new tariffs create a meaningful but manageable headwind," said Angelo Kourkafas, Senior Global Investment Strategist at Edward Jones. This headwind, he explained, affects both sides of the border, driving up steel and aluminum costs for U.S. manufacturers in automotive and construction industries.
Kyle Mohrbach, Senior Executive for North America Automotive at o9 Solutions, a supply chain technology and consulting firm, identified that the greatest vulnerabilities lie with Canadian-sourced, single-sourced, or hard-to-substitute components and materials critical for assembly lines. This includes a wide array of automotive components such as steel, stampings, powertrain parts, braking systems, electronics, and specialized subassemblies.
Why short-term winners in trade wars are hard to trust
Scott Beaulier, Dean of the College of Business and Professor of Economics at the University of Wyoming, drew a clear distinction between benefiting stocks and benefiting businesses. "A tariff can create an immediate scarcity premium for domestic steel and aluminum producers. But the durable winners will be firms that have three things: domestic capacity they can bring online, relatively secure energy and raw-material inputs, and customers unable to easily substitute away from them," Beaulier explained. This defines a much smaller group than simply "American metals companies."
Aluminum serves as a prime example. Beaulier highlighted that the United States remains heavily import-dependent on Canada for primary aluminum. "You can't tariff our dependence away overnight," he said, noting that new smelter capacity is capital- and energy-intensive and takes years to develop. In the interim, tariffs may boost prices for U.S. producers but simultaneously increase input costs for American manufacturers reliant on aluminum. Beaulier cautioned against viewing initial spikes in metals stocks as indicators of lasting economy-wide gains.
Companies are already actively adapting to this volatile situation, according to Melissa Irmen, Director of Advocacy for the National Association of Foreign-Trade Zones. This organization, representing over 1,300 companies and 500,000 employees, has observed significant supply chain shifts and sourcing adjustments. Foreign-trade zones enable companies to import materials into the U.S. without immediate tariffs, allowing for deferment, reduction, or even avoidance of duties if goods are re-exported or reprocessed.
Irmen noted that previous adjustments to trade rules had led to warehousing moving to Canada. Now, companies are considering permanent alterations to their supply chains to circumvent ongoing uncertainty. "All of the tariff uncertainty will permanently change the landscape," Irmen asserted. "Companies are not able to make the fast decisions required for the tariff changes. Supply chains don't work that way." She advises members to think long-term, stating, "Things will not go back to the way they were pre-2025."
The difference between a supply chain and border matters
Experts caution against being swayed by quick positive market reactions. "The stock pop is a headline reflex, honestly — mills reprice to replacement cost the second a 50% wall goes up, so of course Nucor and Cleveland-Cliffs jumped," explained Dan Luttner, Managing Partner at NEOS by Argon & Company, a supply chain consulting firm. He argues the more crucial question is who controls their feedstock internally.
Luttner pointed out that while the SLX and XLB movements reflected instant market repricing, they revealed little about which companies genuinely control their destiny in a trade war. Nucor and Cleveland-Cliffs, operating electric arc furnaces and integrated capacity, are less exposed to Canadian ore or slab, benefiting from the price umbrella. However, Century Aluminum presents a more nuanced case; U.S. primary aluminum capacity is limited, meaning much of its feedstock still crosses the border as alumina or semi-finished products. "So the upside is real, but it's not immune to the same friction it's supposed to be protected from," Luttner said.
Other major metals players, like Freeport-McMoRan (FCX), the third-largest holding in XLB, operate under an entirely different dynamic. Primarily a copper and critical-minerals policy story, Freeport-McMoRan is also currently benefiting from the AI boom.
Luttner underscored that the border itself is a supply chain, not just a line on a map. North American steel and aluminum have operated under an integrated, multi-crossing system for three decades. "Canadian primary aluminum into U.S. extruders, U.S.-melted steel going north for finishing, coming back south inside finished autos and appliances," he detailed. "A tariff doesn't tax that shipment once. It compounds every time the metal re-crosses." Corporate planning teams are now meticulously dissecting bills of materials to identify where parts cross the border repeatedly, as "that's where this actually bites."
This situation differs significantly from other trade chokepoints like the Strait of Hormuz, which is a geographical constraint. "This is policy — the volume can reroute, reshore, or get absorbed into price, it just takes 12 to 24 months of capital and requalification to do it," Luttner explained. He describes it as a "slow-motion reallocation," emphasizing that the real story isn't about immediate stock pops, but rather which manufacturers had already de-risked their supply chains before this week, and which are only now grappling with the complexity of their product's border crossings.

Moody's Sheth stated that the rating agency would closely monitor performance in heavy manufacturing, steel, and aluminum. While larger companies typically possess greater resilience against such shocks, the pervasive uncertainty can inflict the most significant damage as businesses are compelled to reconfigure long-term strategies and supply chains. "Companies won't sit on their hands and wait," Sheth concluded.
—CNBC's Kevin Breuninger contributed to this report.
