CQG offers a suite of Smart Orders that includes auction orders (HKFE-specific).
An auction order is an order to buy or sell in the market at the Calculated Opening Price (COP).These orders are placed without a limit price, and are only for the pre-market opening period. Orders are matched on a time priority basis. Unmatched auction orders are converted to Limit orders at market open.
Placing these orders requires an enablement from CQG and from you in Smart Order Preferences.