AS HE ASCENDED the hierarchy of corporate finance in the 1980s to become king of junk bonds, Michael Milken stood out. Not least physically: he paced the trading floor of Drexel Burnham Lambert sporting a lush but ill-fitting wig. More than 30 years on, junk bonds are a recognised part of the market for raising capital. So are other innovations spawned by the buy-out barons, such as collateralised loan obligations (CLOs), securities into which leveraged loans are packaged. Fast gaining ground on these debt markets is one for private credit, which may now be causing more excitement than any other private market.