According to Bloomberg, Kenneth Rogoff, a former chief economist of the International Monetary Fund (IMF) and member of the Federal Reserve Board, said in an interview that geopolitical tensions and the growing influence of cryptocurrencies are weakening the global status of the dollar. Kenneth Rogoff believes that critics who think cryptocurrencies are just scams and worthless are completely wrong. "It is wrong to believe that there is no 'fundamental value proposition' in cryptocurrency trading." One of the main markets for the U.S. dollar is the global underground economy. In the past, the preferred payment method for such transactions was U.S. dollars, but now the preferred payment method is cryptocurrency. Cryptocurrencies provide a recognized medium of exchange, which is a value proposition. Even if governments strictly regulate cryptocurrencies, they will still face significant challenges in controlling the underground economy. Therefore, Kenneth Rogoff believes that "cryptocurrencies have value." Authorities will face huge difficulties tracking cryptocurrency transactions in the gray market, which means that cryptocurrencies are "not worthless."