PRINCETON (BLOOMBERG) - A US$9 billion (S$12 billion) surge in the past seven days has made Chinese property tycoon Xu Jiayin Asia's second-richest person.

Xu, chairman of China Evergrande Group, has added more wealth than any person on the Bloomberg Billionaires Index this year, a 360.6 per cent rise that has added US$26.7 billion to his fortune.

The 59-year-old Xu, who has a net worth of US$34.1 billion, surpassed India's Mukesh Ambani to become Asia's second-richest person as Evergrande shares jumped amid soaring property sales and the company's shift to a low-debt strategy.

Xu's ascent follows a boom in the value of Chinese real estate assets that has added US$43.8 billion to the fortunes of the country's property tycoons this year, a collective gain of 85 per cent.

Yang Huiyan, vice-chairman and controlling shareholder of Country Garden Holdings, has added US$8.2 billion since the start of the year, while Sunac China Holdings chairman Sun Hongbin, who is a US citizen, is up US$4.2 billion.

Technology billionaires in China have added US$48.9 billion to their wealth this year, which has helped give China's 40-richest people the fastest-growing fortunes on the planet.

Jack Ma, the 52-year-old founder of Alibaba Group Holding and Asia's richest person with US$44.9 billion, has added US$11.6 billion, a gain of 34.7 per cent. Tencent Holdings founder Ma Huateng, 45, has risen US$12 billion, a 57.7 per cent gain that has pushed his net worth to US$32.8 billion, Asia's fifth-largest.