All Exchange Trades and Clearing Agency Transactions are required to be cleared and settled on 2 days after the trade day (T+2).

The HKEX implements enhance the Pre-Opening Session (POS) in securities market on 19 October 2020

The enhanced Pre-opening Session will only cover all equities (including depository receipts, investment companies, preference shares and stapled securities), funds (including Exchange Traded Funds (ETFs) and REITs) and leveraged and inverse products (L&I Products) (together the "POS Securities").

Debt securities, structured products (including Derivative Warrants (DWs), Callable Bull/Bear Contracts (CBBCs) and Inline Warrants (IWs)), equity warrants and rights will not be covered by the enhanced POS. Order and manual trade input on these non-POS Securities during the enhanced POS will be rejected. Trading of these securities, and acceptance of order and manual trade input, will start in the CTS instead.

Pre-opening Session Trading Hours and Periods

The overall duration of the enhanced POS will remain unchanged as compared with the current POS

The HKEX implements the first phrase of Closing Auction Session (CAS) on 25 July 2016.

The coverage of securities in the CAS includes
- Constituent Stocks in Hang Seng Composite LargeCap Index and Hang Seng Composite MidCap Index
- H shares which have corresponding A shares listed on the exchanges in Mainland China
- All ETFs
List of CAS Securities 
https://www.hkex.com.hk/eng/market/sec_tradinfra/vcm_cas/Documents/List%20of%20CAS%20securities.xls

Under the CAS, the market closing time will change from 16:00 to a random closing of anytime between 16:08 and 16:10 for a normal trading day and it will change from 12:00 to a random closing of anytime between 12:08 and 12:10 for a half trading day (i.e. eves of Christmas, New Year and Chinese New Year).

The below are the details of the CAS and the trading arrangement:

Notes:

• The reference price is determined by taking the median of 5 nominal prices in the last minute of the Continuous Trading Session and the system will take 5 snapshots on the nominal prices at 15-second interval starting from 15:59:00.

• Order Input Period: At-auction orders and at-auction limit orders within the ±5 per cent of reference price as price limit.

• No Cancellation Period: At-auction orders and at-auction limit orders can be entered. At-auction limit orders must be between the lowest ask & highest bid recorded at the end of Order Input Period (i.e. recorded at 16:06). 

• Orders outstanding at the end of the preceding Continuous Trading Session will be automatically carried forward to the CAS and treated as at-auction limit orders except that the system will cancel those aggressive orders with prices outside the permissible price limit.

• The market closing time for non CAS securities, structured product (i.e. DWs and CBBCs) and short-selling will continue to be 16:00 for full day trading and 12:00 for half day trading. 

• The price checking in relation to 24-spread rule is not applicable during CAS; while the 9-time rule for at-auction limit order is applicable as usual during CAS.

Details about CAS is available on HKEX website 

HKEX has adopted a dynamic price limit VCM model, which would trigger a cooling-off period in case of abrupt price volatility detected at the instrument level.

The VCM is only applicable for board lot order input during the Continuous Trading Session (CTS), but not for any orders input during the Pre-opening Session (POS) and the CAS. 

During the CTS, the potential trade price of a VCM security will be continuously checked against a dynamic price limit of ±10%, ±15% and ±20% for Hang Seng Composite LargeCap, MidCap and SmallCap Indexes constituent stocks respectively based upon the reference price which is the last traded price 5 minutes ago.

The VCM is triggered if a stock is ±10%, ±15% and ±20% away (for Hang Seng Composite LargeCap, MidCap and SmallCap Indexes constituent stocks respectively) from the last traded price 5-min ago; A 5-min cooling-off period will start.

Normal trading and VCM monitoring will resume on the VCM-triggered instrument after the cooling-off period.

For more information about VCM, please refer to the HKEx website :

                                                                                          More on HKex Website

Clients can place orders through the online trading system outside trading hours. The order you placed will be shown as ‘ wait to handle ‘until the Pre-opening Session at 9:00 am of the next trading day of the Hong Kong Stock Exchange (the Stock Exchange )begins. The‘ wait to handle ‘ orders will be automatically sent to the Stock Exchange for auction trading (At-auction Limit Order) at 9:00 am. 

Official trading of Hong Kong stocks begins at 9:30 am. 

No trading is conducted from 12:00 pm to 1:00 pm,  any orders placed during the period  will be sent to the Stock Exchange for matching after the market begins at 1:00pm.