Double opening means that colleagues buy up and buy down.

Opening more is opening more positions.

Changing hands refers to the transfer of orders in the same direction. For example, if the original bill in my hand is flat, I must have sold it. Someone else must have bought it at this time. If he opened a position, the position in the market did not change at this time, but the list was changed from my hand to his hand. This is called changing hands more. Multi-exchange means that long positions change hands, that is, the old ones sell and close positions, the new ones buy and open positions, and the total market positions remain unchanged. The reason for being empty is the same.