Short futures are not buying and selling wheat. But short selling directly, of course, you will think, how can I sell without wheat? It doesn't matter, the exchange said, you bet on margin. That is, you use your deposit as collateral to sell wheat. (To say the least, it should be. In case you don't close your position, the exchange will use your margin to buy wheat and deliver it to the buyer. However, this situation does not exist. For individuals, the exchange will not let you hold it until the delivery date. It used to be compulsory liquidation. )

So when you sell wheat for 2000 yuan, you don't have wheat in your hand, but there is a short contract, which guarantees your deposit. For an individual, this contract can't be held until the delivery date. Before that, you must hedge, that is, buy back the same number of contracts, but in the opposite direction. So, if you hedge at 1800, then you have the price difference in 200 yuan.