1. When you buy and sell the contract, you only need to pay the deposit. What if you hold a large number of positions and deliver them in the delivery month, and you can't get the full amount when you participate in the delivery? Therefore, when your position exceeds the limit, you should increase the margin and increase your ability to perform.

If you hold such a heavy position, you must be suspected of manipulating the short-term market. Raising the margin will reduce the efficiency of your capital utilization and prevent market manipulation. At the same time, if your position is too large, you should also fill in the report form of large households according to the requirements of the exchange, telling the source of funds, whether there is a spot background, whether there are large households coming in and out together, etc.