Modern Structures

The debt instruments covered in earlier lessons (senior secured loans, mezzanine, unitranche) are the building blocks of deal-level financing. But the PE industry's relationship with debt extends well beyond individual transactions. Over the past decade, several structural innovations have reshaped how PE funds borrow, how leveraged loans get recycled through the financial system, and how interest rate dynamics affect portfolio companies. Understanding these modern structures is essential because they influence fund-level returns, portfolio construction, and the systemic risks that connect PE to the broader credit markets.

CLOs: The Engine Behind the Leveraged Loan Market

A Collateralized Loan Obligation (CLO) is a structured finance vehicle that purchases a diversified pool of leveraged loans (typically 150-300 individual loans) and finances itself by issuing tranches of debt and equity. The CLO's debt tranches are rated from AAA (the safest, lowest-yielding tranche) down to BB or B (the riskiest, highest-yielding tranche). Equity holders sit at the bottom and receive the residual cash flows after all debt tranches are paid.

CLOs are the single largest buyer of leveraged loans in the US market. They purchase approximately 60-70% of all new institutional leveraged loan issuance. This makes CLOs a critical link in the PE financing chain: when a PE sponsor acquires a company and finances it with a Term Loan B, the arranging bank syndicates that loan, and a large portion of it ends up in CLO portfolios. If CLO formation slows (due to rising defaults, regulatory changes, or reduced investor appetite for CLO tranches), the supply of leveraged loan capital shrinks, spreads widen, and PE deal financing becomes more expensive and harder to obtain.

CLOs also have a reinvestment period (typically 4-5 years after issuance) during which the CLO manager can actively trade in and out of loans. This reinvestment activity provides liquidity to the secondary leveraged loan market and allows CLOs to recycle capital from loans that are repaid (via refinancing or company sales) into new loan originations. After the reinvestment period ends, the CLO enters its amortization phase and returns cash to investors as loans mature or are sold.

Floating vs. Fixed Rate: When Each Matters

Leveraged loans are almost always floating rate, priced at SOFR plus a fixed spread. High-yield bonds are almost always fixed rate, with a stated coupon that does not change over the life of the bond. This distinction has significant implications for PE portfolio companies and their sponsors.

When interest rates rise, floating-rate borrowers see their interest expense increase immediately. A company with $500M in floating-rate debt at SOFR + 400 bps saw its annual interest cost rise from roughly $22M (when SOFR was near zero in early 2022) to over $47M (when SOFR exceeded 5% in late 2023). That $25M increase in interest expense flows directly through to reduced free cash flow, lower debt paydown capacity, and weaker coverage ratios. For PE-owned companies with tight coverage, rapid rate increases can push them toward financial distress.

Conversely, when rates fall, floating-rate borrowers benefit immediately. Fixed-rate borrowers do not. This asymmetry is why some PE sponsors use interest rate hedges (swaps or caps) to convert a portion of their floating-rate exposure to effectively fixed. A SOFR cap, for example, sets a maximum rate the borrower will pay, providing downside protection if rates spike while preserving the benefit if rates stay low or decline.

The post-2020 rate cycle illustrated these dynamics vividly. PE portfolio companies that were financed at near-zero rates in 2020-2021 faced a sudden doubling or tripling of interest costs as the Federal Reserve raised rates through 2022-2023. Companies that had purchased rate caps were partially protected. Companies that had not were forced to absorb the full impact, with some requiring sponsor equity cures or covenant amendments to manage through the cycle.