In order to prevent erroneous prices from executing on the exchange, ACDX employs price protections on its market and limit orders.
Price Protection of Market Orders
This is the maximum (buy market) and minimum (sell market) price that can be executed via a market order. If there are remaining unfilled quantities to a market order, the market order will become a resting limit order at the maximum/minimum price.
- Market buy limit protection price = best ask * (1 + market order protection points %)
- Market sell limit protection price = best bid * (1 - market order protection points %)
Price Protection of Limit Orders
This is the maximum buy limit and minimum sell limit price that can be submitted via a limit order. There is no minimum limit on a buy limit price or maximum limit on a sell limit price.
- Buy Limit Price Maximum: Reference Price * (1 + limit order protection point %)
- Sell Limit Price Minimum: Reference Price * (1 - limit order protection point %)
- Buy limit orders more than the Buy Limit Price Maximum and sell limit orders less than the Sell Limit Price Minimum will be rejected
- If an order is a Stop Limit Order, the Reference Price is the Stop Price, otherwise it is chosen in the following order:
- Last Trade Price
- if the last auction did not have a fill, go to 2
- Best bid if it is higher than, or best ask if it is lower than, the previous Mark Price
- If best bid or best ask did not go through the previous Mark Price, go to 3
- Mark Price