Long-short and double-open currency security contracts mean that two-way positions hold the same futures contract in both directions. Holding a position in the same direction is a reverse position. There are empty orders and many orders. This practice is to reduce risks, losses and profits, which can also be understood as adding 0.5 leverage. Holding positions in the same direction refers to opening one-to-many orders and adding several orders, or opening empty orders and adding several orders. One-way (multiple orders or empty orders) billing is risky. Once it succeeds, it will make a big profit, and once it fails, it will also be a big loss.