Dexin-B (02526) rose 21.1% to HK$600, with turnover of 30,000 shares worth HK$17.73 million, according to ETNet.
The stock hit a high of HK$600 and a low of HK$465. At 9:49 AM, the move triggered the market volatility control mechanism and sent the shares into a five-minute cooling-off period, during which trading was limited to between HK$446.4 and HK$603.5. Normal trading was scheduled to resume at 9:54 AM. Dexin-B is a constituent of the Hang Seng Composite MidCap Index, and the mechanism is triggered when a stock's price moves more than 15% from the last traded price five minutes earlier during continuous trading sessions.