What is Volatility Control Mechanism (VCM)?Volatility Control Mechanism

A cooling-off period Hong Kong applies to some large stocks: if the price moves too far from the reference price within a few minutes, a 5-minute cooling-off starts in which trades can only happen inside a set price band.

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Hong Kong Stock Rules
No Price Limits and the Volatility Control Mechanism (VCM)
Hong Kong has no daily price limit, so big news can move a stock sharply within the day; some large stocks have the VCM, which forces a 5-minute cooling-off when the price moves too far too fast.

Related terms

stop-loss
price limit
volatility interruption

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