The whole process of futures trading can be summarized as opening positions, holding positions, closing positions or physical delivery. Opening a position, also known as opening a position, refers to the new purchase or sale of a certain number of futures contracts by traders. An open contract after opening a position is called an open contract or an open contract, also known as a position. Before the end of the last trading day, choose an opportunity to sell the bought futures contract or buy back the sold futures contract, that is, cancel the original futures contract through a futures transaction with the same amount and the opposite direction, thus ending the futures transaction and relieving the obligation of physical delivery at maturity. This behavior of buying back a sold contract or selling a bought contract is called liquidation.