Wall Street is already handing out verdicts on who will win and who will lose if President Trump follows the Commerce Department's recommendations to impose heavy tariffs on steel and aluminum imports.
American steel stocks spiked on Friday immediately after the Commerce Secretary Wilbur Ross proposed actions aimed at reviving the beleaguered steel industry.
Nucor, the largest U.S. steel maker, climbed 4%, while U.S. Steel and AK Steel soared more than 10% apiece.
Ross recommended an across-the-board tariff of 24% on imports from all countries, or tariffs of at least 53% on imports from 12 countries in particular, including China and Russia. Ross also suggested limiting imports of steel into the United States.
Aluminum stocks also bounced, led by an 8% jump for Century Aluminum. Larger American aluminum makers like Alcoa, Arconic and Reliance Steel & Aluminum also ticked higher. Aluminum prices climbed nearly 2% on the news.
The Commerce Department recommended a tariff of 7.7% in aluminum imports from all countries, or a tariff of 23.6% on imports from five specific countries. The proposal also includes a proposal to cut aluminum imports from most countries by 13%.
But if the proposed tariffs and quotas lift prices on aluminum and steel, the trade action could create headaches for auto, appliance and plane manufacturers - and their customers.
Shares of General Motors, Ford and Whirlpool declined about 2% apiece. Ford is already grappling with higher costs. The automaker warned last month that commodity costs will squeeze 2018 profits.
Even beer companies, which use aluminum to make their millions of cans, could be hurt.
Molson Coors Brewing, the maker of Coors Light and Miller Light, reportedly warned last year that aluminum duties would "obviously get passed on to us and the customer."
On the other hand, tariffs could help steel and aluminum makers regain market share lost to cheaper imports from China, Russia and elsewhere. Higher prices could pad their bottom lines as well.
The American steel industry has loudly pushed for help from Trump. More than two dozen U.S. steel and steel-related companies and associations wrote Trump a letter on February 2 urging "strong action" to support domestic steel.
"Now is the time for Presidential action to prevent excess steel capacity and surging steel imports from undermining our national security and the viability of the U.S. steel industry," the companies stated.
It's far too early to know how the Trump administration's proposed tariffs would shake out in the long run. One risk is that aggressive action sparks a trade war that hurts the broader economy.
- CNN's Patrick Gillespie contributed to this report.