Macroscopically, the relationship between the dollar index and the price of crude oil is analyzed: the dollar is the most powerful currency in international circulation, and crude oil is also a commodity in international circulation. International commodities are all priced in dollars, so the value of commodities priced in dollars will decrease (relatively) after the appreciation of dollars, which shows that the relationship between dollars and crude oil is reversed.

Dollar and crude oil are international assets. In the case of constant money supply, if more funds flow into the dollar market, it means that some funds flow out of the crude oil market, thus suppressing the price of crude oil. On the other hand, if more funds flow into the crude oil market, it means that some funds will flow out of the dollar market, thus suppressing the dollar.

Macroscopically, the dollar has always maintained a long-term negative correlation with crude oil.

From the perspective of economics, the relationship between the US dollar index and crude oil price is analyzed again: as the pricing currency of international crude oil price, the US dollar has a much higher impact on crude oil price than other currencies such as euro and Japanese yen.

The changing principle of currency exchange rate will also affect the trend of crude oil price.

Theoretically, when the dollar index weakens, crude oil denominated in dollars will be very cheap and demand will rise from the perspective of euro or yen; On the other hand, when the dollar appreciates, the price of crude oil denominated in euros or yen will be very expensive, and the demand for crude oil will decrease.