Some people call it as empty as empty.
The object of futures trading is standardized contract, which is a purchase contract in the form of "order". The contract stipulates the time for the physical and payment transactions (one or several days in the future), and there is no need to pay for the goods in one hand and deliver them in the other (in fact, stocks are spot transactions). Buyers and sellers only need to "pay" a deposit of about 10% of the purchase price to the exchange.
Therefore, for short investors, as long as they think that the price of a futures product will fall, they can "sell the goods first" at the current price when there is no spot, that is, open a futures sell order and complete the delivery with the spot when the contract expires. At this time, if the variety really falls as investors judge, then he can buy the spot at a lower price in the market and deliver it to the contract holder, who needs to pay the payment at the agreed price at that time, so that the short investors can get the difference income. Of course, short sellers can also transfer to other investors before the contract expires, and get benefits in advance; At the same time, you can also close the position with the other party by agreement, and you don't need to deliver the spot, you can also get the spread income.