Russia’s currency is tumbling after Western nations on Saturday agreed to put crippling sanctions on the country’s financial sector in retaliation for its invasion of Ukraine.
The ruble fell about 30% against the dollar Monday — making it worth less than 1 U.S. cent — after the U.S., European Union and United Kingdom announced moves to block some Russian banks from the SWIFT international payment system and to restrict Russia’s use of its massive foreign currency reserves. The system is used to move billions of dollars around more than 11,000 banks and other…