When an investor buys a long euro contract, it is said that the investor holds a long euro contract; If you short the euro, that means investors are short the euro. When investors sell their short positions in euros back to the market, it is called liquidation. There are generally two ways to close the position (that is, close the position), one is to hedge the position; The second is physical delivery. Physical delivery is to fulfill the responsibility of futures trading through physical delivery. Therefore, futures delivery refers to the behavior of buyers and sellers of futures trading to make physical delivery of their respective expired open contracts in accordance with the provisions of the exchange when the contracts expire and end their futures trading. From the perspective of the stock index futures market as a whole, bulls and bears must be equal, because contracts need to be traded, and both buyers and sellers are indispensable. Therefore, when any transaction is completed in the stock index futures market, long and short positions will change in the same amount and direction. Opening trades will increase the same number of long and short positions, while closing trades will decrease the same number of long and short positions.