Hedging is the most common in the futures market, aiming at avoiding the risk of one-way trading. The so-called single-line trading means buying short positions (or short positions) when you are optimistic about a certain variety, and selling short positions (short positions) when you are bearish on a certain variety. If the judgment is correct, the profit will naturally be more; But if the judgment is wrong, the loss will not be greater than not hedging.
The so-called hedging is to buy a variety at the same time and then short it. In addition, there is another variety to sell, that is, shorting. In theory, short selling a variety and short selling a variety should be the same as the silver code, which is the real hedging, otherwise the hedging function cannot be realized if the two sides are different in size.