(Bloomberg) -- As private companies, Uber Technologies Inc. and Lyft Inc. became markets unto themselves, where investors poured in capital and traded stakes worth billions of dollars. Since both companies filed paperwork confidentially Thursday for an initial public offering, several investors are poised to cash in on their bets next year in a big way.

The filings submitted by Uber and Lyft aren’t yet public, but people familiar with each business outlined the largest shareholders. They aren’t, for the most part, Silicon Valley venture capitalists. The top holders of America’s main ride-hailing companies are both from Japan: SoftBank Group Corp. and Rakuten Inc., said the people, who asked not to be identified because they weren’t authorized to discuss the information publicly.

Matt Kallman, a spokesman for Uber, and Alexandra LaManna, a spokeswoman for Lyft, declined to comment.

SoftBank, a Japanese conglomerate run by Masayoshi Son, owns more than 15 percent of Uber. Rakuten, an e-commerce company that began amassing a sizable stake in Lyft when the startup appeared to be an also-ran, now owns more than 10 percent. Together, their stakes would be worth at least $13 billion. Japan has the largest taxi market in the world, but the government has effectively shut out most ride-hailing companies. That, perhaps, encouraged investors there to look westward.

American venture capitalists will still have plenty to celebrate, especially those at Benchmark and Andreessen Horowitz. Benchmark, an early Uber investor, is poised to generate a historic return. The firm is the second-largest owner of Uber with more than 5 percent of shares. Lyft counts Andreessen Horowitz among its top five shareholders.

Uber’s bankers have said the company could be worth $120 billion in an IPO, while Lyft is targeting $18 billion to $30 billion, people familiar with the matter have said. Here’s a breakdown of each company’s backers:

Uber’s largest shareholders

Lyft’s largest shareholders

• The e-commerce company Rakuten owns more than 10 percent of Lyft. Rakuten CEO Hiroshi Mikitani sits on the ride-hailing company’s board. When other investors were nervous about Lyft’s future, Rakuten doubled down on the second-place player.
• General Motors Co. invested $500 million in Lyft a couple years ago. It was supposed to be the start of a beautiful friendship, where the two companies would work together on self-driving cars and auto leasing. Instead, that relationship has frayed. But GM stands to make out well from its investment.
• Mutual fund manager Fidelity owns a stake in both Uber and Lyft, though it has a significantly larger percentage of Lyft, with more than 5 percent of shares.
• Andreessen Horowitz invested in Lyft back in 2013. The venture capital firm has bought and sold shares since them. It still owns more than 5 percent, unlike another VC firm, Peter Thiel’s Founders Fund, which also bought in early but has a smaller stake today.
• Lyft co-founders Logan Green and John Zimmer together own about 7 percent of Lyft shares. They had to give up a great deal of control over the years to fund an expensive rivalry with Uber.
• Other significant investors include Alphabet, through the investment fund CapitalG, and VC firm Mayfield Fund.

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