As we can see from the above picture, the US dollar index has greatly appreciated twice. During these two sharp appreciation periods, as the US dollar is the main commodity pricing currency in the world at present, the strength of the US dollar is bound to suppress commodity prices. Commodity prices such as energy (first cycle), precious metals, basic metals and agricultural products (second cycle) all fell. Although the influence of supply and demand will affect the price trend of a certain kind of goods in the short and medium term, in the long run, the negative correlation between commodity prices and the US dollar is more obvious. At present, the investment market recognizes that the US dollar index is negatively correlated with commodity futures.