Customer Margin

Investors must deposit margins to place an order for a transaction such as hedge, arbitrage, and speculation transaction that increases the open interests.

The amount of margin of an investor without any open interest (initial margin; only for the orders that increase the open interests of a certain contract)
  • For the buy and sell orders of futures trading: previous day's base price of the underlying asset × customer margin rate (half or more of the margin amount must be deposited in cash)
  • For of the orders of futures spread trading: order quantity × spread customer margin (the whole amount can be deposited with substitute securities)
  • For the buy orders of options: the whole order amount (in cash only)
  • For the sell orders of options: the larger of (a), (b), and (c) (the whole amount can be deposited with substitute securities, at the member's discretion)

(a) [multiplier x (theoretical price of option adjustment margin* - base price of option customer margin) x 30%] * The theoretical price when the underlying asset's base price goes up or down as much as the twice of the customer margin rate

(b) [multiplier x (theoretical price of option margin - base price of option customer margin)]

(c) Minimum margin amount per contract

The amount of margins of an investor with open interests (margin for the unmatched orders + margin for the matched orders)
  • If an investor with open interests places an order for the first time or places another order following an order already placed, the margin is calculated taking into account the margin for the unmatched order and the open interests as well as the margin for the order to be placed.
  • The margin for the matched order is calculated by adding the margin for the already held open interest (the maximum net risk exposure from the derivatives trading; the option price margin plus the larger of the net risk customer margin and the minimum net risk customer margin) and the amount to be settled (the sum of the daily futures net loss, the daily options net purchase amount, settlement amount for the day, and the next day's settlement amount) and deducting the next day's settlement amount therefrom.

In cases where an investor places an order for the first time after opening of the derivatives account, or places an order before 12:00 of the next day after liquidating all the open interests, the investor is required to deposit the derivatives basic deposit of which schedule is set by the member considering the credit status, etc. of customers. The deposit is appropriated as customer margin.


For the qualified institutional investors such as banks, financial investment companies, etc. the margin at the time of order placement is exempted, while they are required to deposit the customers' margin by the time the member designates within 10:00 of the next trading day, which is called the ex-post customer margin. The customer margin is calculated by adding the next day's settlement amount to the net risk margin for the open interests at the closing of the market.

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  • Equity Derivatives Rules & Regulations 051-662-2625