In addition, take the British pound and the US dollar as examples (don't take the RMB as an example, because the RMB is a non-tradable currency, and the black market or a small amount of exchange is not included). In fact, the foreign exchange market and the stock market are the same. If there is no big problem in the country, then more people want to buy than sell, then it will appreciate, and vice versa. If the British government wants to appreciate, it only needs to buy pounds. At that time, you always didn't have to buy pounds with pounds, but you had to use dollars. If you want to depreciate, it is very simple. If you print the pound hard, it will naturally fall.