Jack Ma, executive chairman of Alibaba Group Holding Ltd (BABA.N), has become China’s richest man with a fortune estimated at $25 billion, underscoring the ascension of tech tycoons over real estate peers in the world’s second biggest economy. Ma knocked Wang Jianlin, head of the Wanda property group, into second place with $24.2 billion, according to this year’s list of China’s super-rich published by Hurun Reports Inc.