Exports are converted into dollar-denominated figures in the United States, and then the same amount of RMB is issued in China (some companies that have both exports and imports will settle part of their exports for import). This is the main reason why the RMB has gone up and down, and it is also the reason why the growth of China's foreign exchange reserves is much higher than the total surplus. In fact, China's foreign exchange reserves (basically) have no value, they are just proof of the overseas pricing of the equivalent RMB.