They are a go-to vehicle for charities, university endowments and pension funds that need at least 8% in annual returns to meet obligations. Yale University, for example, keeps roughly one-third of its endowment funds with them.

The good news is you don't have to be a part of the wealthy elite to participate in private equity's outsized returns. That's because about a dozen of them now trade on stock exchanges... They've become an oxymoron -- publicly listed private equity firms.