ChainCatcher news, according to Bloomberg, Kenneth Rogoff, former chief economist of the International Monetary Fund (IMF) and a member of the Federal Reserve Board, stated in an interview that geopolitical tensions and the growing influence of cryptocurrencies are undermining the global position of the dollar.Kenneth Rogoff believes that critics who think cryptocurrencies are just scams with no value are completely wrong. "The view that there is no 'fundamental value proposition' in cryptocurrency transactions is incorrect." One of the main markets for the dollar is the global underground economy, where the preferred payment method for such transactions used to be the dollar, but now the preferred payment method is cryptocurrency. Cryptocurrencies provide a recognized medium of exchange, which is a value proposition. Even with strict government regulation of cryptocurrencies, there will still be significant challenges in controlling the underground economy. Therefore, Kenneth Rogoff believes that "cryptocurrencies have value." Authorities will face enormous difficulties in tracking cryptocurrency transactions in the gray market, which means that cryptocurrencies are "not worthless."