The Stock Exchange of Hong Kong commenced trading in 1986 after the unification of the four exchanges.
The Hong Kong Exchanges and Clearing Limited (HKEx) engages in listing and trading activities via the Stock Exchange of Hong Kong Limited (SEHK), which, in turn, operates the main board and the Growth Enterprise Market. SEHK deals in a variety of investment instruments ranging from equity securities to exchange traded funds to derivative warrants, callable bull/bear contracts, real estate investment trusts and debt securities.
On July 25, 2016, HKEx added the Closing Auction Session(CAS) as its second bidding period. During this brief additional session of 8 to 10 minutes, market participants such as index-tracking fund managers may execute buy and sell orders at a "closing price" following a bidding process.
CAS determines a certain price point based on the greatest demand. Upon receiving buy or sell orders from market participants, SEHK's trading mechanism analyzes the orders according to their buy or sell nature, their price points and the time they are are placed to run a matching process. The price point commanding the highest trading volume will become the closing price.