VCM Enhancements Initiative

HKEX concluded in December 2019 to enhance the Pre-Opening Session (POS) and Volatility Control Mechanism (VCM) in its securities market.  The VCM enhancements covers expanded stock coverage, tiered triggering thresholds and allowing multiple triggers in a later phase to further reduce risks caused by individual stocks’ price volatility, reflecting changes in international practice and regulatory guidance.  This page focuses on the implementation details of the VCM enhancements.

Market Consultation

• Consultation Paper and Questionnaire
• Consultation Conclusions

Presentation Materials

• Briefing Session on Enhancements Implementation (Video/ PDF)
• Briefing Sessions on Market Consultation

FAQ 

• FAQ for VCM

Circular

• Amendments to the Rules of the Exchange (the “Rules”) 
• Practice Session, Rollout Test and Launch Date for Volatility Control Mechanism (VCM) Phase 2 Enhancement and Expansion of Order Queue Size 
• Commencement of End-To-End (E2E) Test Session for Volatility Control Mechanism (VCM) Phase 2 Enhancement 
• Implementation of Multiple Triggers for Volatility Control Mechanism (VCM) in the Securities Market
• Launch of Volatility Control Mechanism (VCM) Phase 1 Enhancement on 11 May 2020    
• Market Education Materials for Volatility Control Mechanism (VCM) Enhancement    
• Practice Session for Volatility Control Mechanism (VCM)
• Volatility Control Mechanism (VCM) and Pre-opening Session (POS) Enhancements in the Securities Market – Implementation Details
• Consultation Paper and Briefing Sessions on Market Microstructure Enhancements in the Securities Market
• HKEX to Enhance Pre-opening Session (POS) and Volatility Control Mechanism (VCM) in the Securities Market

Other Reference Materials

• VCM Information Book (Updated as of 20 Sep 2024) [NEW]
• VCM Securities List
• VCM Cooling-off Period Trigger History
• VCM Infographic (Updated as of 3 May 2022) 
• Press Release: HKEX to Implement VCM First Phase Enhancements on 11 May
• Press Release: HKEX Consults Market on Proposed Microstructure Enhancement in the Securities Market
• Press Release: HKEX to Enhance Pre-Opening Session and Volatility Control Mechanism in its Securities Market