The most important exchange rate in the international foreign exchange market should be the exchange rate between the US dollar and other currencies (the best understood is the US dollar index). The dollar index can be said to be the basis for calculating the exchange rate of all transactions. The dollar index represents the American economy, which in turn affects the global economy. Therefore, many people will pay attention to the trend of the US dollar index in addition to technical news. We can basically look at the US dollar index, and there are several currencies that can be used. For example, Europe and America, pounds, America, Australia and America. This is very direct. It can be seen that when the US dollar index rises, the European and American pounds, the United States, Austria and the United States fall (regardless of other factors).