tougher sanctions on russia and its central bank. michelle fleury in new york explains why it's so significant. bitcoin, the world's largest cryptocurrency, rose 10% to over $41,000 at one stage, and ethereum jumped nearly 8%. it comes amid reports that binance — the biggest crypto exchange — will not be blocking the accounts of russian users, despite calls to do so. ukrainian vice prime minister tweeting on sunday, "i'm asking all major crypto exchanges to block addresses of russian users. it is crucial to freeze not only the addresses linked to russian and belarusian politicians, but also to sabotage ordinary users." the worry is that, without access to the global financial system, russia will try to use cryptocurrency to get around western sanctions. meanwhile, in ukraine, millions of bitcoins have poured in from donors to try to help. with cryptocurrencies, there is now a tool that makes it easy to move vast sums of money across borders, to the benefit of both sides.