For example, there are two contracts for rebar, and the quantity of each contract is 10 ton. The settlement price of the day is 1830 yuan/ton, and the margin ratio of the futures company is 12%. The required margin should be: 1830 * 12% = If the funds in your account are less than this amount, you need to add a margin. For example, after today's closing, the settlement price becomes 1.820 yuan, the futures price drops by 10 point, and the capital you invested that day happens to be 4,392 yuan, so you need to add a margin of 200 yuan.