HKSI Paper 8 Stock market administration question: at-auction limit order

Answer: A. It cannot be cancelled, as 9:15 a.m. to 9:20 a.m. is the no-cancellation period

The Pre-opening Session runs from 9:00 a.m. to 9:30 a.m. in four periods: order input (9:00-9:15 a.m.), when at-auction and at-auction limit orders can be entered, amended or cancelled; no-cancellation (9:15-9:20 a.m.), when new orders may be entered but none can be amended or cancelled; random matching (9:20 a.m. to up to 9:22 a.m.); and blocking until 9:30 a.m. Mr Siu's request at 9:17 a.m. falls in the no-cancellation period. He could have cancelled up to 9:15 a.m., so a ban from the moment of entry is wrong; the right to cancel does not run to 9:20 a.m.; and the Stage 2 limits govern the prices of new orders, not cancellations. Source: HKEX, Trading Mechanism of the Pre-opening Session in the Securities Market (version 10 April 2026), section 3; Rules of the Exchange, Chapter 5 (as at October 2026).