Lei Jun, the 48-year-old founder and CEO of Xiaomi, the world's fourth-largest smartphone maker by shipments, has an estimated real-time net worth of $19.5 billion as of July 13, exceeding Robin Li of Baidu and Richard Liu Qiangdong of JD, and ranking 118th on the 2018 billionaires net worth list, according to Forbes.

Xiaomi debuted on the Hong Kong Stock Exchange on Monday with an offering price of HK$17 ($2.17), the first to list in Hong Kong with a dual-class structure, allowing founders to have more voting rights.

The listing has made five of its eight co-founders billionaires, Forbes said. According to Xiaomi's prospectus, Lei and co-founder Lin Bin hold more than 40 percent of the shares in Xiaomi, while more than 7,000 of its employees hold company shares or options. In April, Lei already got a bonus of $1.5 billion worth of company stock for his contributions to the company, one of the biggest executive bonuses in history.

Early investors have also made a lot of profits from the Xiaomi listing, Securities Daily reported. In an open letter issued on the eve of the listing, Lei Jun revealed that Xiaomi's first venture capitalist has recouped its early investment of $5 million 866 times over after the listing. Firms such as Morningside Venture Capital, Qiming Venture Capital and Shunwei Capital were the biggest winners.