In futures trading, any trader must pay a small amount of funds according to a certain proportion of the value of the futures contract (usually 5%- 15%) as the financial guarantee for his performance of the futures contract, and then he can participate in the futures contract trading and decide whether to add funds according to the price change. This system is the deposit system, and the money paid is the deposit. \ x0d \ x0d \ In China, futures margin (hereinafter referred to as margin) can be divided into settlement reserve and trading margin according to its nature and function. \x0d\ 1。 Calculation formula of settlement reserve: \x0d\ balance of settlement reserve on the current day = balance of settlement reserve on the previous trading day+transaction margin on the previous trading day+actual offset amount on the current day-actual offset amount on the previous trading day+current profit and loss+current deposit-current withdrawal-transaction fee+other funds \x0d\ calculation formula of transaction fee: ∑ [volume (hand)] Trading margin \x0d\ Trading margin refers to the margin actually paid by member companies or customers for holding futures contracts in futures trading. Divided into initial deposit and additional deposit: \x0d\ 1. Initial margin \x0d\ Initial margin is the funds that traders need to pay when they open a new position. According to the transaction amount and margin ratio, that is, initial margin = transaction amount and margin ratio. At present, the minimum margin ratio in China is 5% of the transaction amount, which is generally between 3% and 8% internationally. For example, the soybean margin ratio of Dalian Commodity Exchange is 5%. When a customer buys five soybean futures contracts (each 10 ton) at a price of 2,700 yuan/ton, he needs to pay an initial deposit of 6 750 yuan to the exchange (that is, 2,700× 5×10× 5%). \x0d\ In the process of holding positions, there will be floating profit and loss (the difference between settlement price and transaction price) due to the constant changes of market conditions, so the funds actually available in the margin account can be increased or decreased at any time. Floating profit will increase the balance of margin account, while floating loss will decrease the balance of margin account. The minimum balance that must be kept in the margin account is called maintenance margin. Maintenance margin: the settlement price is adjusted to the position, and the margin ratio is adjusted to xk(k is a constant, which is called the maintenance margin ratio, which is usually 0.75 in China). \x0d\ 2。 Additional margin \x0d\ When the book balance of margin is lower than the maintenance margin, the trader must add margin within the specified time, so that the balance in the margin account is ≥ settlement price x position x margin ratio, otherwise, the exchange or institution has the right to force liquidation on the next trading day. This part of the margin that needs to be replenished is called additional margin. Still according to the above example, suppose that on the third day after the customer bought 50 tons of soybeans at a price of 2700 yuan/ton, the settlement price of soybeans fell to the additional margin. 2600 yuan/ton. Due to the price drop, the customer's floating loss is 5000 yuan (i.e.