Mezzanine investors blossomed in private equity’s boom era. After it reached a peak in 2006, the financial crisis stifled its growth.

The debt specialists, which invest in the tranche between junior and senior debt, piled into leveraged buyout loans, helping fund the mega-deals of 2005 to 2007. While in 2000, mezzanine debt issuance in Europe stood at $2.6bn, it reached a peak of $26.3bn in 2006, according to data provider Dealogic.