Baltimore-based sports apparel company Under Armour saw its shares decline by more than 18%, to $5.36, as markets closed Thursday.

After President Donald Trump suggested U.S. tariffs would focus on China, Mexico and Canada, Under Armour said in February that import levies would not “impact our business significantly.” The company added at the time that it would “stay vigilant” for additional tariffs.

Those additional tariffs have arrived.

A self-proclaimed “Tariff Man,” Trump fully earned that moniker this week by listing dozens of countries that would face substantial tariffs. The impacted countries range from Western allies to Southeastern Asian nations, many of which are large producers of apparel sold worldwide.

Businesses scrambled Thursday, as the S&P 500 declined almost 5% — its worst drop since 2020.

Apparel companies including Under Armour were hit especially hard as Vietnam, a top apparel producer, was slammed with a 46% tariff.

Like other American apparel companies, Under Armour imports the vast majority of the goods it sells domestically.

Lance Allega, senior vice president of investor relations, declined to specify in February which countries are the company’s leading manufacturers “for propriety and competitive reasons,” but said its products sold in the U.S. come from more than 15 countries.

In a statement Thursday, Under Armour said, “this is an evolving issue that Under Armour is monitoring alongside the industry.”

“Given the dynamic nature of various tariff policies to date with respect to depth, breadth, and tenure, we will await more details and then assess potential business impacts to determine what, if any, actions we may or may not [choose] to employ,” Allega wrote in an email Wednesday.

Economists have projected that Trump’s widespread tariffs will result in companies passing along the extra costs to consumers.