Credit ratings play a central role in the structured finance market. They help investors compare risk across asset classes, determine regulatory capital requirements, and influence the cost of funding for issuers. In Canada, securitized transactions are typically rated by DBRS Morningstar, Moody’s, S&P Global Ratings and Fitch Ratings. Although each agency has its own methodology, core principles are common: analysis of collateral performance, structural features, legal considerations and the macroeconomic environment.
Why are ratings important? Ratings signal credit quality and default probability. Many institutional investors – such as pension funds and insurance companies – can only invest in securities that meet minimum rating thresholds. Regulators also refer ratings when setting risk weights for bank capital. For Canadian ABS, a rating downgrade can increase funding costs or trigger early amortization events.
What do rating agencies consider? While methodologies vary by asset class, key components include:
- Collateral quality: Agencies examine credit scores, loan‑to‑value ratios, payment histories and geographic concentrations.
- Structural protections: Ratings assess subordination, reserve accounts, excess spread and performance triggers. Agencies expect loss‑absorbing junior tranches to protect senior notes, consistent with the Basel definition of a traditional securitization.
- Legal and regulatory framework: The enforceability of security interests, bankruptcy remoteness of the special‑purpose vehicle and the presence of adequate documentation are critical. The Bank of Canada report on disclosure emphasises that standardized documentation and transparency support market confidence.
- Macroeconomic factors: Expectations of unemployment, GDP growth, interest rates and housing prices feed into stress scenarios. Agencies update assumptions regularly; for instance, rising interest rates and inflation may lead to higher loss expectations in auto and consumer ABS.
How should issuers and investors use ratings? Ratings are an informed opinion, not a guarantee. Investors should perform their own due diligence, reviewing collateral data, structural features and legal opinions. Issuers should engage with rating agencies early in the structuring process, provide transparent data and respond to feedback. For cross‑border deals, differences in Canadian and US regulatory environments (e.g., treatment of NHA MBS as non‑securitizations) must be considered.
Key learnings
- Credit quality and structure drive ratings. Agencies focus on collateral performance and the ability of credit enhancement to absorb losses. Robust junior tranches, reserve accounts and triggers are essential for high ratings.
- Legal and regulatory certainty matter. Bankruptcy‑remote structures, enforceable collateral security and clear documentation underpin investor confidence. Standardized reporting and transparency reduce information asymmetry.
- Ratings are dynamic. Agencies revise assumptions as macro conditions change. Rising interest rates, changing consumer behaviour or new regulatory rules can lead to rating revisions. Issuers should maintain dialogue with agencies and provide timely performance data.
References: Bank of Canada, Residential Mortgage Securitization in Canada: A Review (insured mortgages and public securitization); OSFI Capital Adequacy Requirements Chapter 6 (definition of traditional securitization and credit subordination); Bank of Canada, Securitized Products, Disclosure and the Reduction of Systemic Risk (importance of disclosure and standardized documentation).