The State Department announced Wednesday that the sanctions would be handed down for what it determined was Russia's use of a chemical agent, Novichok, to poison former Russian spy Sergei Skripal and his daughter Yulia in Salisbury, England, in March.
Fears of further sanctions sent the ruble down 3 percent on Wednesday. The dollar hit its highest level against the ruble since November 2016, with one dollar buying as many as 66.7099 rubles on Thursday morning. The greenback is up 5.8 percent against the Russian currency since the end of July, and up 14.6 percent since the start of this year. The ruble recovered slightly from its low to 65.8750 at 12:45 p.m. Moscow time (5:45 a.m. ET).
Moscow's dollar-denominated RTS, an index of 50 Russian stocks traded on the Moscow exchange, is down 2.14 percent, with financials and industrials hardest hit so far, both down more than 2.6 percent. Russian's flagship airliner Aeroflot has fallen by 4 percent and state bank VTB is down by 3.9 percent. Russian banks have been listed as targets of various U.S. sanctions bills currently being floated in Congress.
The ruble-denominated benchmark MOEX was less affected, down roughly half a percentage point at time of writing. Russian sovereign dollar bonds fell across the curve, with the yield on Russia's 10-year bond at a year-high of 8.08 percent. Bond prices move inversely to yields.
The sanctions, which will impact Russian exports of electronics and other national security-controlled equipment, will go into effect around August 22, according to the State Department. The decision was triggered by the U.S. government's conclusion that the Kremlin violated a 1991 international law against chemical and biological warfare.