Blackstone Taps Vast Source of Cash in $1 Trillion Credit Push

A couple of years ago Clive Cowdery had a problem. The large life insurer that he’d founded was amassing customer cash faster than it could find ways to put that hoard to work.

As payments piled up at Resolution Life, two of every three dollars sat idle. The company decided it couldn’t hang around for its in-house crew to scour the globe for the bonds, mortgages and other assets in which insurers typically invest people’s money. So it turned to Blackstone Inc.

Like fellow “alternative” investment titans Apollo Global Management Inc. and KKR & Co., Blackstone has been ...