Credit Rating
Key Takeaways
- Credit ratings assess the ability and willingness of a borrower to repay debt
- The three major agencies are Moody's, S&P Global, and Fitch Ratings
- Investment grade is BBB-/Baa3 and above; below is speculative/junk
- Rating changes significantly impact bond prices and borrowing costs
Definition
A credit rating is an assessment of the creditworthiness of a borrower — their ability and willingness to repay debt obligations. Credit ratings are assigned to countries, companies, and specific debt instruments by specialized rating agencies. The three dominant agencies are Moody's Investors Service, S&P Global Ratings, and Fitch Ratings.
Ratings use letter-based scales: S&P and Fitch use AAA (highest quality) through D (default). Moody's uses Aaa through C. The critical dividing line is between investment grade (BBB-/Baa3 and above) and speculative grade, also called high-yield or junk (BB+/Ba1 and below). This line matters enormously because many institutional investors are restricted from holding non-investment-grade debt.
Credit ratings directly influence borrowing costs. A downgrade means a company must pay higher interest rates to borrow, while an upgrade reduces borrowing costs. For bondholders, downgrades cause price declines and upgrades cause price increases.
How It Works
Rating agencies evaluate creditworthiness based on financial metrics (debt-to-equity ratio, interest coverage, free cash flow), business characteristics (industry position, diversification, management quality), and macroeconomic factors. They also assess the specific terms of each debt instrument, including seniority, collateral, and covenants.
The rating scale from highest to lowest: S&P/Fitch: AAA, AA+, AA, AA-, A+, A, A-, BBB+, BBB, BBB- (investment grade) | BB+, BB, BB-, B+, B, B-, CCC+, CCC, CCC-, CC, C, D (speculative grade). Moody's equivalent: Aaa, Aa1-Aa3, A1-A3, Baa1-Baa3 | Ba1-Ba3, B1-B3, Caa1-Caa3, Ca, C.
Rating agencies also provide outlooks (positive, stable, negative) and watchlist designations that signal potential future rating changes. A negative outlook does not guarantee a downgrade but indicates the agency sees increasing risk.
Example
When S&P downgraded General Electric (GE) from A to BBB+ in 2018, and later to BBB (one notch above junk), GE's borrowing costs increased by approximately 0.5-1.0 percentage points on new debt. GE's existing bonds fell in price as investors demanded higher yields. The company was forced to cut its dividend and sell assets to strengthen its balance sheet and preserve its investment-grade rating. A downgrade to junk status would have been catastrophic, as many institutional investors would have been forced to sell GE bonds.
Why It Matters
Credit ratings are gatekeepers of the bond market. Institutional investors — pension funds, insurance companies, mutual funds — often have mandates requiring investment-grade holdings. A downgrade to junk triggers forced selling by these institutions, creating a cascade of price declines. This dynamic makes the investment-grade threshold one of the most important lines in corporate finance.
For individual investors, credit ratings provide a standardized assessment of bond risk. While not infallible (the agencies failed to flag risks before the 2008 crisis), ratings remain the primary language of credit risk and are essential for evaluating corporate bond investments.
Advantages
- Provide standardized, widely accepted assessment of credit risk
- Enable comparison across thousands of bond issuers globally
- Rating changes serve as early warning signals for credit deterioration
- Reduce information asymmetry between issuers and investors
Limitations
- Rating agencies failed to identify risks before the 2008 financial crisis
- Potential conflicts of interest — issuers pay for their own ratings
- Ratings are backward-looking and may lag market perception of risk
- Ratings are opinions, not guarantees of repayment
Frequently Asked Questions
Related Terms
Browse more definitions in the financial terms glossary.