Social Finance—better known as SoFi—is a private company that began in 2011 as a peer-to-peer social lender for student loan refinancing, explains Ian Wyatt, editor of Million Dollar Portfolio.

With roughly 200 employees, SoFi is a small company. Even so, the company has made more than $1.75 billion of loans. According to SoFi, it's saved the average borrower $11,783. This year, SoFi expects to underwrite $4 billion of loans.

That's attracted lots of attention from investors. In total, SoFi has now raised $766 million. Soon after this latest round, Bloomberg reported that Social Finance was aiming for a $3.5 billion valuation in a 2015 IPO.

And while you can't invest directly in SoFi, there is a secret way to get invested before an IPO. You can invest in a little-known stock called Renren (RENN), a venture capital firm based in Beijing.

Renren was originally dubbed the "Facebook of China." But its core business has languished, with revenues  cut in half between 2012 and 2014.

At the same time, Renren has been making a series of strategic investments in tech firms that are innovating the finance sector. In total, Renren has invested in more than 30 venture capital deals.

The biggest of those investments is the firm's $89 million investment in SoFi, a 24.8% stake. And that's why you should consider buying the stock.

Another one of Renren's recent investments is in Cheyipai, a leading online used car marketplace, operating in 163 cities. Another is Motif Investing, an online brokerage firm that makes it easy to invest in ideas or themes.

And in April, Renren led a $70 million investment in LendingHome. The peer-to-peer mortgage lender has already originated more than $100 million of mortgages in the last year.

In another deal, Renren invested with noted hedge fund manager Kyle Bass.  Renren invested $50 million in Bass's Japan hedge fund and another $30 million in his pharmaceutical patent fund.

Overall, based on my analysis, the shares are worth at least $5.27. That provides at least 31% upside from the current price. However, the long-term upside could be far greater.

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