Simply put, a country holds a variety of foreign exchange reserves (currencies that can be used as reserves, such as gold and dollars), which are large and can bear great financial risks. In other words, others are not afraid of what happens in this country. In case of currency problems, the foreign exchange in hand is still very valuable, and vice versa. If the country runs well and has so much money to buy foreign exchange, it also proves that the overall economic strength of the country is at least not bad, but it may be good. The country has development prospects, steady pace, healthy economic growth, trade surplus and high foreign exchange reserves, which proves that the country is very good and strong. Then, it cannot be said that its currency does not appreciate. As long as you know that money is the expression of commodity value and reflects the strength of a country's economy, everything else can be seen to prove whether this country is strong or not. Of course, this is simple, but the details are not clear.