Yahoo earned a $9.4 billion windfall from selling 140 million shares in the Chinese e-commerce giant.

We knew Yahoo was going to score big with its investment in Chinese e-commerce giant Alibaba, which raised a record $25 billion in a recent initial public offering. Now, it’s official.

Yahoo took in $9.4 billion by selling 140 million shares in Alibaba’s IPO, according to a regulatory filing.

Yahoo’s windfall represents a blockbuster investment and a huge opportunity for CEO Marissa Mayer. She has yet to say what she will do with the money. But she may use it for acquisitions and buying back shares to help prop up her company’s stock price. Wall Street, however, is dubious about her managing any the money well and are valuing Yahoo for little beyond its cash hoard and remaining Asian investments.

Following the IPO, Yahoo retains 383 million Alibaba shares, representing a 15% stake in the company.

Yahoo YHOO 0.00% left some money on the table by selling in the IPO at the offering price of $68. Those Alibaba shares BABA -2.85% have since increased in value to $88.85 at the close of trading on Tuesday.

And along with Yahoo’s windfall from Alibaba, Japanese tech giant Softbank also gained from its 34% stake in the company. Softbank’s founder Masayoshi Son became the richest man in Japan – on paper, at least – as his net worth reached $16.2 billion after the IPO.

Alibaba co-founder Jack Ma, meanwhile, becameChina’s richest man with a net worth of $25 billion.