Trump’s Russia Sanctions Just Halved a Major Company’s Stock Price

April 9, 2018, 10:51 AM UTC

When the United States hit Russian oligarchs and senior political officials with new sanctions on Friday, the move had a pretty swift effect on at least one of its targets.

Oleg Deripaska described the sanctions on him and companies associated with him as “groundless, ridiculous and absurd.” However, on Monday his aluminum-producing giant, Rusal, lost half its value.

Rusal’s shares dropped 50.4% on Hong Kong’s Hang Seng index today. In Moscow, Rusal’s stock lost a third of its value in Monday morning trading. Also on the Moscow Exchange, Nornickel—the nickel and palladium operation in which Deripaska holds a quarter stake—lost 16% of its value before recovering slightly.

Meanwhile, EN+—the Deripaska-controlled holding company that co-owns Rusal—was down around 22% on the London Stock Exchange on Monday morning. And Glencore (GLNCY), the commodity trading and mining giant that also happens to be a big shareholder in Rusal, and its biggest customer, lost more than 3% on the LSE.

Last week’s sanctions forbid U.S. entities from doing business with the people and firms on the list.

Deripaska’s inclusion was a big deal. The billionaire has very close ties to Russian President Vladimir Putin, and he notoriously employed political consultant Paul Manafort—now at the center of the U.S. probe into Russian election interference—for years.

The list also included Kirill Shamalov, Putin’s son-in-law (although Bloomberg reported earlier this year that he and Katerina Tikhonova, Putin’s youngest daughter, had split.)

Subscribe to Well Adjusted, our newsletter full of simple strategies to work smarter and live better, from the Fortune Well team. Sign up today.