Digital Sky spent a reported $400 million buying up Facebook stock last year, and followed up that investment by leading huge rounds at what are arguably the two hottest internet startups right now, Zynga and Groupon. It also beat out several other bidders to buy IM service ICQ from AOL (NYSE: AOL) for $187.5 million in late April.

SEE ALSO: DST Reportedly More Than Doubles Stake In Facebook

The company’s own ownership structure has shifted in recent months. South African media corporation Naspers took a 28.7 stake in Digital Sky in July in exchange for cash and a stake in Russian e-mail service Mail.ru, which Digital Sky now completely controls. Tencent, the big Chinese internet company, also invested $300 million in Digital Sky in April in exchange for a 10.26 percent stake. All in all, the company says it has raised more than $1 billion in funding. The WSJ says Digital Sky has a $4 billion valuation.

—A little irony? Digital Sky CEO Yuri Milner and partner Alexander Tomas have both said very publicly that companies should be cautious when they consider going public. A choice quote from Milner in December on the topic of whether Zynga should go public: “When it’s just a liquidity-driven IPO, it might be suboptimal because liquidity can be provided through a private transaction rather than a public one, with all the costs and distractions associated with that.” And here’s Tomas on Facebook and an IPO there: “It’s just a natural evolution and I think by trying to push that too hard on a company, you more disrupt than do good.”

To be fair, we don’t know what’s driving Digital Sky’s own desire for an IPO now. A spokeswoman wouldn’t comment to the WSJ about the report, only saying that “an IPO was always in DST’s strategic agenda.” And, indeed, Milner had said a year ago that the company’s “model” was to exit through an IPO likely “within the next three years.”  We’ve asked for additional details and will update if we hear back.