Auction Trading to Capture Opportunities
Pre-opening session, which is 30 minutes before the commencement of the morning session of the continuous trading session. The closing auction session commences one minute after the continuous trading session and ends at random closing time between 16:08 and 16:10 on a normal trading day (12:08 and 12:10 on a half trading day) as determined by HKEX system.
During pre-opening session and closing auction session, you can place two types of orders: "At-auction Order" & "At-auction Limit Order". (Please note that "Order Watching Service" option is not applicable)
At-auction Order
At-Auction Order is a market order without a specified price with higher auction matching priority than At-auction Limit Order. During pre-opening session, new at-auction order can only be placed on stocks eligible for pre-opening session and during closing auction session, new at-auction order can only be placed on stocks eligible for closing auction. The executed price / volume will be determined on the final Indicative Equilibrium Price (IEP)* and Indicative Equilibrium Volume (IEV)#. Depending on market conditions, not all At-auction orders can be matched. If the order placed at either pre-opening session or closing auction session is unfilled at the end of that session, the order will be cancelled automatically . Please note that the executed price (i.e. final IEP) is not known at the time of order input and may not fall within or largely deviate from your expected price range, especially for orders executed in pre-opening session. The Bank reserves the right to sell the related securities to setoff the cash shortfall.
At-auction Limit OrderΔ
HKEX will only accept at-auction orders for stocks eligible for pre-opening session (POS) or closing auction session (CAS) only. For an order that cannot be executed due to ineligible for POS nor CAS, the order status will change from "Pending Dealing" to "Unexecuted". You can check the updated status of your order in the "Order Status". If you are using our Instant Order Confirmation Service, you will receive related SMS.
At-Auction Limit order is a limit order with a specified price. The executed price / volume will be determined on the final Indicative Equilibrium Price (IEP)* and Indicative Equilibrium Volume (IEV)#. After market close till end of pre-opening session on next trading day, new At-Auction limit order can be placed on stocks eligible for pre-opening session but the order price must be within HKEX permissible price limit. Please ensure at auction limit order price entered is within HKEX permissible price limit, or else the order cannot be executed in the market. For an order that cannot be executed due to outside HKEX permissible price limit, the order status will change from "Pending Dealing" to "Unexecuted". You can check the updated status of your order in the "Order Status". If you are using our Instant Order Confirmation Service, you will receive related SMS. At pre-opening session (including at-auction limit orders received after random matching starts), unfilled or partially-filled orders will continue to be processed at your specified price in the continuous trading session.
For stocks eligible for closing auction trading, if the corresponding order cannot be fully executed in the continuous trading session and the order price is within HKEX permissible price limit, the order will be carried forward to the closing auction session by HKEX automatically. During closing auction session, new at-auction limit order can be placed on stocks eligible for closing auction trading but the order price must be within HKEX permissible price limit. When auction matching is completed, unfilled order will be cancelled. For stocks not eligible for closing auction trading, if the corresponding order cannot be fully executed in the continuous trading session, unfilled orders will be cancelled after continuous trading session ends.
Upper/Lower Price (applicable to Pre-Opening Session and Closing Auction Session)
HKEX impose a price limit on At-Auction limit orders during pre-opening session. For stocks with previous closing price, during Order Input Period, the upper/lower price will be ±15% of previous closing price. During No Cancellation Period and Random Matching Period, the upper price for buy is the highest bid at 9:15 or the lowest ask at 9:15 (whichever is higher) while the lower price for buy is -15% of previous closing price. The lower price for sell is the lowest ask at 9:15 or the highest bid at 9:15 (whichever is lower) while the upper price for sell is +15% of previous closing price.
For stocks without previous closing price (e.g. IPO stocks or stocks resuming from trading suspension), during Order Input Period, there will be no upper/lower price limit (but the existing 9-times price limit will also applicable to POS). During No Cancellation Period and Random Matching Period, the upper price for buy is the highest bid at 9:15 or the lowest ask at 9:15 (whichever is higher) while there is no lower price limit. The lower price for sell is the lowest ask at 9:15 or the highest bid at 9:15 (whichever is lower) while there is no upper price limit.
Price limit is imposed during closing auction session on limit orders carried over from continuous trading session to closing auction session and newly input at-auction limit orders to prevent excessive price movement. During Reference Price Fixing Period, HKEX will determine the reference price for each closing auction eligible stock. The upper/lower price at Order Input Period will be ±5% of the reference price. During No Cancellation Period and Random Closing Period, the upper/lower price limit will be the highest bid and lowest ask price.
Auction Trading Timetable
To fully capture the opportunities in the pre-opening and closing auction session for trading securities, you can refer to the following timetables for auction trading.
Pre-opening Session Timetable
Closing Auction Session Timetable
Should you have any queries on the above service, please contact our Customer Service Hotline 2822 0228. For details of the trading mechanism of HKEX during pre-opening session and closing auction session, please visit the website of HKEX: www.hkex.com.hk.