Hong Kong Exchanges and Clearing Limited (HKEx) announced today (Monday) that its cash market will introduce five-digit stock codes on 7 April 2008 subject to market readiness.

In view of the growing number of new listings in recent years and to support future growth in structured products, HKEx considers it necessary to expand the stock codes from the current four digits to five digits and for practitioners in the Hong Kong cash market to prepare for such change.  The implementation of five-digit stock codes will not only offer more stock code capacity to support future market growth but also provide flexibility to standardise and rationalise stock code classification.  With the range extended to 1-99999, it will be possible to apply new coding conventions to better differentiate products and information. 

In order to reduce system and operational changes for Exchange Participants and other market users, HKEx will assign five-digit codes to newly listed structured products only at the initial stage.  Apart from being preceded by a zero, existing stock codes and AMS/3* information page numbers will in general not be affected and remain within the range of 1 to 9999.

All existing HKEx core IT systems – such as AMS/3, CCASS/3*, the Market Datafeed System (MDF), the Issuer Information feed Service, the e-Submission System, the HKEx websites, and HKEx supplied trading devices including on-floor and off-floor terminals, the Multi-workstation System and Open Gateways (OG) – were built to support five-digit stock codes.  In particular, five-digit stock codes have been the standard data format used for the OG interface with the Broker Supplied Systems (BSS) since the launch of AMS/3 in October 2000.  This ensures that all existing BSS support the five-digit stock code format in all message communication vis-à-vis AMS/3.  Similarly, the system specifications of the Participant Gateway interface in CCASS/3 have mandated five-digit stock codes as the standard format since May 2003.  The message format of MDF is also able to support 5-digit stock codes.

HKEx will conduct seminars, testing sessions and rehearsals for market participants and promote public awareness via education materials before implementing five-digit stock codes on 7 April 2008.