Option margin refers to the amount of self-owned funds that you must deposit with the broker in order to start trading. Technically, there are two types of deposits-initial deposits and maintenance deposits. Maintenance margin is the amount of money that brokers ask you to increase in order to maintain the ratio of their own funds to borrowed funds at an appropriate level. Put option is actually put option, and buying put option means bearish market outlook.

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I. Calculation formula of option deposit

The margin of options can be divided into the following three types:

(1) Opening margin refers to the margin calculated when an investor opens an option contract;

(2) Maintenance margin refers to the margin that investors need to pay when holding open contracts at the end of the day;

(3) Real-time margin refers to the margin calculated on a daily basis according to the latest price of the target and the latest price of the option contract, which is used for real-time risk monitoring of investors' accounts.

According to the types of contract targets, Shanghai and Shenzhen Stock Exchanges have formulated different formulas for calculating option deposits. For the subject matter of a stock contract, the formula for calculating the deposit of each contract is as follows:

For contracts with ETF as the target, the deposit calculation formula for each contract is as follows:

The Shanghai and Shenzhen Stock Exchanges clearly stipulate that the margin charged by securities institutions to investors shall not be lower than the standards set by the stock exchanges and China. The option deposits charged by different securities institutions are different. Most securities companies charge 10%-30% on the basis of stock exchanges.

When investors sell and open positions, they need to calculate the opening margin required for investment according to the opening margin. The opening deposit is only used for front-end control and is not actually collected. When the investor's available margin balance is less than the corresponding opening margin amount, the selling opening declaration is invalid. After the investor sells and opens the position, the intraday options trading system will calculate the real-time margin according to the latest price of the target and the latest price of the option contract. After the liquidation, the securities company will calculate the maintenance margin according to the closing price of the target and the settlement price of the option contract. Investors will return the occupied margin in real time after closing the open position contract.