The pre-market opening session (POS) helps establish an orderly market open when the trading system is loaded with large numbers of orders and provides the market with a fair mechanism to determine the calculated opening prices (COP) at which the largest possible number of contracts may be traded, based on a predetermined formula. This helps to maintain order at the market open and minimise price fluctuation. During the pre-market opening session, the COP is established before the market open without matching orders.
At present, the pre-market opening is only available for the trading of HSI, MHI, HHI and MCH futures contracts, MSCI Taiwan Index related futures contracts and Hang Seng TECH Index futures contracts.
A random cutoff mechanism is applied to the pre-opening session and the pre-open allocation session. This enhancement aims to deter the possible gaming strategy of manipulating the COP near the end of the auction process and also to encourage order input at an earlier stage. It will be applied to the POS for both morning and afternoon sessions of the applicable markets.