OKEx price limit rules are introduced to protect investors and prevent market manipulation. Option buyers are required to follow maximum price limit rules, while option sellers are required to follow minimum price limit rules.

OKEx take into account a number of parameters, including the options mark price and Delta for risk control system. In order to give users a better understanding of our risk control system and facilitate options trading, the formulae for calculating the maximum bid price and the minimum ask price are as follows:

Maximum bid price = options mark price + adjustment coefficient * max (1, 4 * abs (Delta))

Minimum ask price = options mark price - adjustment coefficient * max (1, 4 * abs (Delta))

OKEx will adjust the above coefficients depending on the market conditions and the adjustment coefficients of different index option contracts are different. OKEx price limit rules are implemented under the tick size requirements. Normal users are required to follow our price limit rules while posting orders under normal circumstances and during partial liquidation.