Meaning
Internal mechanism within a financial security that improves the credit profile of a specific debt tranche through the design of the cash flow. A structural credit enhancement often uses subordination, where losses are first absorbed by lower tiers of investors. This arrangement allows the senior notes to achieve a higher credit rating than the underlying pool of assets would otherwise support.
It functions by redirecting the order of payment to protect the most senior participants from default.
Tranche Priority
Distribution of cash follows a waterfall where the top levels are paid before the bottom levels receive anything. This structural credit enhancement creates a hierarchy of safety within a single issuance. If the underlying assets underperform, the junior tranches lose their value first, acting as a cushion for the rest.
This design attracts different types of investors with varying tolerances for risk.
Default Buffer
Excess spread and overcollateralization provide an additional layer of protection. A structural credit enhancement often includes a requirement that the value of the assets stays higher than the value of the debt issued. The extra interest collected from the borrowers is held in a reserve fund to cover future defaults.
These internal buffers ensure that the security can survive a period of economic stress without missing a payment.
Investor Protection
Ratings agencies evaluate the strength of these arrangements before assigning a grade to the bonds. A strong structural credit enhancement can lift a pool of average loans to a triple A rating. This process opens up new sources of funding for the originator of the debt.
The final security relies more on its own architecture than on the strength of any single borrower.