1. If it is determined that the price of crude oil will rise, you can buy it first and then sell it. The significance of this operation is actually to buy crude oil at the current price, and then sell crude oil after the price of crude oil rises, so as to profit from the price difference. Sell before you buy:
1. If you think the price of crude oil will fall, you can sell it first and then buy it. This operation can be understood as borrowing a certain amount of crude oil from the bank to sell, then waiting for the price of crude oil to fall, and then buying crude oil back to the bank at a lower price, thus making a profit.