IOC Feature：Price Protection Mechanism for Spot Trading

A new Immediate or Cancel(IOC) feature is now available in KuCoin spot trading. It is designed to prevent execution issues which may lead to unnecessary loss when placing orders. The specific rules are as follows:

If a limit/market order can be executed in Spot trading, the system will determine whether the deviation between the price corresponding to the market depth and the best ask/bid price exceeds a certain threshold.

If exceed the threshold, a limit order will fail to be placed, and a market order can be partially executed(the exceeding part of this market order will be canceled). 

For example, if a user placed a market order to buy KCS in KCS/BTC, the best ask price at the moment is 0.00012BTC, and the system determines the last price will reach 0.0002BTC if this order is filled. Assume that the deviation is 10% and the threshold price is 0.00015BTC, based on the calculation of (0.0002-0.00012)/0.00012=66.7%>10%, this order can be executed till 0.00015BTC while the remaining quantity will be canceled.

Kindly reminder:
1. IOC mode may have deviations in market depth detection. If the order cannot be executed completely, the quantity may exceed the threshold.
2. The threshold is different for every trading pair, which can be obtained from the API symbol port.