China's foreign exchange reserves include a basket of currencies, such as the US dollar and the euro. Of course, most of them are dollars (mainly because the trade volume between us and the United States is too high, and international settlement, such as buying oil from Middle Eastern countries and buying minerals from Australia, needs dollars). China only holds 900 billion US Treasury bonds, and its foreign exchange reserves are 2 trillion. Others also buy bonds and stocks of other countries, and the structure is very complicated.