The combined net worth of Russia’s wealthiest people fell by 16 billion U.S. dollars Monday -- erasing all of their year-to-year gains -- following last week’s U.S.-imposed sanctions, according to Bloomberg.

All but one of the 27 Russian tycoons listed on the Bloomberg Billionaires Index lost money, led by Siberian nickel miner Vladimir Potanin, whose fortune declined US$2.25 billion. Lukoil PJSC Chief Executive Officer Vagit Alekperov saw his wealth tumble US$1.37 billion, while Viktor Vekselberg of Renova Group lost US$1.28 billion, Bloomberg reported on April 10.

Oleg Deripaska, who was also among those sanctioned, reportedly lost $905 million on April 10 and has seen his fortune dwindle by more than US$2 billion over the past two trading days.

His losses stemmed from his industrial conglomerate En+ Group Plc, whose shares have plunged 54 percent since April 5, according to London Stock Exchange data.  Through EN+, Deripaska owns half of United Co. Rusal, the giant aluminum producer that was also slapped with sanctions.

Oleg Deripaska’s net worth plunged $1.1 billion on April 6y to a record low for the year, Bloomberg said on April 9.  He is one of seven Russian tycoons sanctioned last week by the Trump administration under a law Congress passed to retaliate against Moscow for meddling in the 2016 U.S. presidential election.  His fortune has dropped by more than US$2 billion this year, more than any other wealthy Russian, according to the Bloomberg Billionaires Index.