If investors buy bullish contracts, if futures fall below the limit, then investors can only sell them by hanging orders, so they need to pay attention to the risk of short positions. If the margin is not added after the short position, the investor may be forced to close the position, and all expenses arising from the short position shall be borne by the investor.

If investors buy bearish contracts, if futures fall, it means that investors have made money and can close their positions. If he thinks that the future futures will fall, he can continue to hold it.