Companies are expected to sell between $55 billion to $65 billion of junk bonds and leveraged loans next month.
Recent junk-rated issuers include Royal Caribbean Cruises and SeaWorld.
Companies are rushing to take advantage of the booming leveraged loan market.
Public unitranches have a structure similar to a type of loan used in private credit's playbook.
U.S. leveraged loan prices have fallen to the lowest level since December 2020 as investors flee riskier assets.