President Donald Trump made good on his promise to impose steep tariffs on America’s three largest trading partners — Canada, China and Mexico — citing a national emergency on the flow of fentanyl and undocumented immigrants into the United States.

Trump’s tariffs on Mexico and Canada are giving a boost to some steelmakers’ stocks, but retaliatory tariffs could reduce the potential benefits.

That doesn’t seem like a lot, but it can impact the price of the entire market—and the cost structure of steel users. Shares of domestic steel producers all started in the gre