A wave of demand from mainland Chinese buyers is restoring liquidity to Hong Kong’s trophy home market, enabling owners who have held onto pricey assets for many years to lock in gains.Among them, mainland property tycoon Zhao Zhijun sold two adjoining units at 8-12 Peak Road for a combined HK$320 million (US$40.8 million), according to Land Registry records, generating a gain of about 86 per cent compared with the purchase price 16 years ago.Zhao, chairman of mainland investment firm Niverse,...