Shares in the aluminum company owned by Oleg Deripaska—the Russian billionaire with close links to former Donald Trump campaign manager Paul Manafort—have nosedived after he was named as one of 24 Russian businessmen and officials hit with U.S. sanctions. Shares in Rusal plunged 50 percent in Hong Kong trading after the sanctions, announced last week, cast doubt on the future of the company’s banking and trading relationships. Rusal is the biggest aluminum company outside of China and Deripaska was one of the most high-profile figures hit by the sanctions intended to punish Russia for actions in Crimea, Ukraine, and Syria, and attempting to subvert Western democracies. Russian opposition figure Alexey Navalny previously claimed Deripaska acted as a conduit between the Trump campaign and the Kremlin.