How Gargantuan Can Private Equity Get?

Stephen Schwarzman has a simple mission for Blackstone, the world’s biggest listed private-equity group: double assets under management. For a group that already has $434 billion up from less than $100 billion a decade ago, that sounds ambitious, but Blackstone isn’t alone.

The biggest private-equity firms are in a fund-raising frenzy, fed by insurers’ and pension funds’ hunt for yield and a conviction that private markets will produce better returns than highly liquid and efficient public markets.