Usually used for futures operation, it is also called diversion/reversal in our bank. Take gold futures as an example. For example, if you buy a hand when the price of gold is $65,438+0,000, when the price rises to $65,438+0,0 0 10/0, you already have a profit of $65,438 +00. You think the price of gold will not rise, but may fall back, so you want to sell and close your position. Operation equals to selling 2 lots, closing positions 1 lot and placing new orders 1 lot. No need to knock, the same price can do two actions! You got it? Ask again if you don't understand!