Crude oil is bought and sold according to contracts, which expire every month. Before the expiration date, you can choose to move the warehouse or offset it.

Futures contracts for crude oil are often one a month. Futures contracts do not exist forever like stocks, but are settled once a month. So at this time, one of the contracts we hold has expired, so we need to go to the next contract to buy so many current positions and market values, and then continue to hold them. For example, crude oil 2005 refers to the contract for delivery and settlement in May 2020. If you still have your contract when it expires, then we need to pick it up. If it is moved into the contract when it expires in June, then we need not worry about it.

So there is an obvious technical term in futures investment, which refers to the most active contract of investors. The main contract is often variable. If this month is a May contract, then when the May contract is about to be delivered, investors will close the position of the May contract and then switch to the position of the June contract. At this point, investors who stay in the May contract will wait for the spot delivery due. During this period, speculators will transfer the expired contract to June, and the contract in June will become the new main contract.