The one-bedroom in Cheung Sha Wan was listed at HK$4.1 million on a Thursday. By Sunday it had three offers. The agent told the owner to wait. May's residential transaction value reached HK$57.8 billion -- up 71.5% from April, per the Lands Registry -- and the owners who listed in March at the wrong price are watching their neighbours collect. The surge ran on two engines: stamp duty settings held since February, and a wave of mainland buyers moving ahead of Beijing's new cross-border property purchase restrictions, announced in late May, before the rules could close.

SAFE's new guidance limits individual offshore property transfers by quarter; the implementation notice went to banks in the week of May 26. It does not reach transactions already signed. The Land Registry closing backlog is running four to six weeks behind signing dates, which means buyers who committed in the first three weeks of May will settle clean. June's Land Registry data will show whether mainland demand holds at any volume under the quarterly cap. The HK$4.1 million flat went for HK$4.35 million on Monday.