If the futures reverse, it is not to collect money, but to stop the loss in time, otherwise your whole family will lose money.
Short selling refers to the phenomenon that when shorting stocks or futures, brokers are forced to close their positions because the market fluctuation is too large and the margin cannot deduct the losses.
Short-selling profits from falling asset prices. Shorting stocks and futures requires a certain margin. The theoretical margin is 10% of the actual position value, which means that the actual reverse fluctuation that investors can bear is only 10%.