On Alibaba’s big day, Jack Ma is an $18 billion winner by Benjamin Snyder @FortuneMagazine September 19, 2014, 6:32 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons With Alibaba’s first big day on the New York Stock Exchange come and gone, the dust has settled leaving CEO Jack Ma with $18 billion – on paper, at least. Ma, who founded the company in his apartment in Hangzhou 15 years ago, was worth $13 billion as of Thursday when shares were priced at $68. But that rocketed to $5 billion higher after Friday’s close. On Friday, shares closed at $93.89 up 38% from the initial pricing, meaning Ma’s stake in the company soared to just over $18 billion. The company’s total market value now exceeds $231 billion. Ma sold 12.75 million shares in the IPO, which is just a fraction of his 206.1 million total ahead of the IPO. That sale earned him $867 million. Ma, of course, wasn’t the only one to earn big from the Chinese e-commerce giant’s public debut. Yahoo, too, has cause to celebrate. The tech company is making billions from the 121.7 million shares of Alibaba it is selling. Yahoo, however, ended trading on Friday down about 3%. There’s also Softbank CEO Masayoshi Son, who owns a big Alibaba stake, who became the richest man in Japan following the Alibaba IPO. Son saw his net worth jump to of $16.6 billion after Softbank’s shares gained 16% since last week. The company, meanwhile, holds a 34% stake in Alibaba Group.