This is necessary because you will pay a certain amount of money in your account first. If you make money, you can take out the money other than the deposit. If you are unlucky to lose money, the company will put forward the amount in your deposit, and then inform you to make up the insufficient deposit before you can continue to place an order.

Why do you even have to pay money first? Because people are mobile. If one day you lose money, but you can't find anyone, who will be responsible for the money?

Doing futures is risky, because sometimes there is a big gap between profit and loss because of market fluctuation, so I must set a stop-loss point, that is, if the market is contrary to my list, I may be able to bear 100, but jumping out of 200 points will make me very troublesome, so I must set a stop-loss point as a guarantee.