First of all, futures contracts are standardized contracts, but the price of standardized contracts is uncertain.

That's how your deal is done. On the trading software, if you sell the sugar with an opening price of 1 hand of 4,800 yuan (assuming a deal is made), then the margin is 4,800 *1*10 *12% = 5,760, which is the trading margin.

When the price changes to 4,700, buy and close the position, and gain100 *10 *1=1000 yuan.

Finally, buying a position is equivalent to the goods you promised to sell to others. If you buy a position at 4700, you have already opened another contract and signed another contract. This is the correct list of locks.