Number of recent transactions on hand

Opening a position refers to opening a new long position or a new short position, that is, buying or selling a certain number of stock index futures contracts.

If you have opened a long position, you need to sell your contract to hedge your position. If you have already opened a position, you need to buy some contracts to hedge your position. Simply put, your own position is 0. If you buy 1 first, which is equivalent to 0+ 1= 1, you need to sell 1 contract1= 0. If you sell 1 first, it is equivalent to 0- 1.