As mainland China tightens its tax rules, can Hong Kong remain a magnet for billionaires?

For decades, Hong Kong has been a magnet for the rich. From wealthy Chinese setting up family trusts to millionaires migrating from across Southeast Asia, all of them have been sucked in by the city’s promise of free capital flows, a trustworthy legal system and extensive financial expertise. It is a winning combination that helped Hong Kong leapfrog Switzerland as the world’s biggest cross-border wealth hub last year, as the city rode a wave of blockbuster listings by Chinese technology...