Introduction

What is Closing Auction Session (CAS)?

The Closing Auction Session allows orders to be entered into the trading system for a single price auction which consists of a reference price fixing period, an order input period, a no cancellation period, and a random closing period as follows:

*Eves of Christmas, New Year and Lunar New Year

What is Reference Price Fixing Period?

In this period, a reference price which sets the allowable price limit of CAS (±5% from the reference price) is calculated for each CAS security. 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.

What is Order Input Period?

In this period, at-auction orders and at-auction limit orders within the ±5% price limit can be entered on CAS securities. Outstanding orders can also be amended or cancelled during this period.

What is No Cancellation Period?

In this period, at-auction orders and at-auction limit orders can be entered. However, the prices of new at-auction limit orders must be between the lowest ask and highest bid recorded at the end of the Order Input Period (i.e. recorded at 16:06), and no orders can be amended or cancelled.

What is Random Closing Period?

In this period, the order rules from the No Cancellation period apply, and the market closes randomly within two minutes.

What securities are covered under CAS?

1. All equities, including:
   1. Depository receipts
   2. Investment companies
   3. Preference shares; and
   4. Staple securities
2. Funds, including
   1. Exchange Traded Funds (ETFs) ; and
   2. Real Estate Investment Trusts (REITS)
3. Leveraged and Inverse Products.

Our Closing Auction Service

How do I trade in the Closing Auction Session?

Limit orders not filled in the preceding Continuous Trading Session will be automatically converted into at-auction limit orders in CAS. You can also input new at-auction limit orders before the random closing of the market.

Can I place market order in the Closing Auction Session?

No. Market order can only be placed and processed in the Continuous Trading Session. (9:30 am – 12 pm and 1:00 pm – 4:00 pm HKT).

Can I change / cancel my orders in the Closing Auction Session?

You can change or cancel your orders during the Order Input Period.

What happens to my order if it is not filled in the Closing Auction Session?

Orders that should expire at the end of the day will lapse. Good Till Date orders not yet expired will be carried forward to the next trading day.

What if I do not want my orders automatically enter into the Closing Auction Session?

You should cancel your order during the Order Input Period.