The Stamp Duty (Amendment) Bill 2022 was passed on 18 January. It gives effect to the proposed exemption of stamp duty payable for some transactions regarding dual-counter stock made by market makers. The amended Ordinance was effective on 27 January 2023. The HKEX plans to formally launch the Dual Counter Market Making Programme within these months.
Resource: https://www.elegislation.gov.hk/hk/2022/11/18/supp3/2!en