closing position = closing position, which means selling what was originally bought, and buying what was originally sold (short).

The whole process of futures trading can be summarized as opening positions, holding positions, closing positions or physical delivery. Opening a position, also called opening a position, refers to the new purchase or sale of a certain number of futures contracts by traders. In the futures market, buying or selling a futures contract is equivalent to signing a forward delivery contract. If the trader keeps the futures contract until the end of the last trading day, he must settle the futures transaction through physical delivery or cash settlement. However, only a few people make physical delivery, and most speculators and hedgers generally choose to sell the futures contracts they bought or buy back the futures contracts they sold before the end of the last trading day. That is to say, the original futures contract is written off by a futures transaction with the same amount and the opposite direction, so as to terminate the obligation of physical delivery at maturity. This behavior of buying back a sold contract or selling a bought contract is called liquidation. A contract that has not been closed after opening a position is called an open contract or an open position, also called a position. Traders can choose two ways to close futures contracts after opening positions: either choose the opportunity to close positions, or keep them until the last trading day and make physical delivery.

short selling means selling something you don't own. You can borrow shares from your broker and sell them in the market. The proceeds will be credited to your account, and there will be a record of your short selling ("owing") of stocks. Finally, you must buy back the stock to fill your previous short position or sell (return the stock to the owner, that is, your broker). For example, suppose that the current market price of Hutchison Whampoa is 12 yuan. You believe that the share price will fall to 11 yuan soon. At this time, you can short 1 shares and yellow shares in 12 yuan, so that your account will be credited with 12, yuan and earn interest. After three days, if Hutchison's share price falls to 11 yuan, you can buy back 1, shares from the market for 11, yuan, and then return the shares to your broker.