Credit Spreads - The Price of Default Risk
By EC Assets Research Team, Fixed Income Research · Published · Updated
Credit Spreads: A credit spread is the extra yield a borrower pays over a comparable risk-free benchmark - the market's price for default risk, loss given default, and lower liquidity. The spread, not the absolute yield, is what credit investors trade, and it is one of the most reliable real-time barometers of financial stress.
What a Credit Spread Is
A credit spread is the extra yield a borrower pays over a comparable risk-free benchmark, usually a government bond of the same maturity. If a 5-year corporate bond yields 5.40 percent and the 5-year government bond 4.40 percent, the spread is 100 basis points. Credit investors trade and analyse the spread rather than the yield, because it separates the issuer's risk from the level of interest rates set along the yield curve.
How It Works
A first-order decomposition is
$$\text{Spread} \approx \text{PD} \times \text{LGD} + \text{risk premium} + \text{liquidity premium}$$
where PD is the annual probability of default and LGD the loss given default. The first term is the expected credit loss. Observed spreads are much wider than expected losses alone justify, the so-called credit spread puzzle. Elton, Gruber, Agrawal and Mann (2001) attribute most of the corporate spread to risk premia and taxes, Huang and Huang (2012) find that structural default models explain only a small share for investment-grade bonds, and Longstaff, Mithal and Neis (2005), comparing bonds with credit default swaps, identify a separate liquidity component.
The simple yield difference is refined in practice:
G-spread. Yield over the government curve interpolated to the bond's maturity.
Z-spread. The constant spread added to the whole risk-free zero curve that reprices the bond.
Option-adjusted spread. The Z-spread after removing the value of embedded options, the standard measure for callable bonds and credit indices.
A spread move changes the price through spread duration, which for a fixed-coupon bond is close to its modified duration: %ΔP ≈ -spread duration × Δspread.
Worked Example
A 5-year bond pays an annual coupon of 5.40 percent, trades at par and sits 100 basis points over the 5-year government yield of 4.40 percent.
What the spread pays for. Assume an annual default probability of 0.30 percent and a loss given default of 60 percent. Expected loss is 0.30% × 60% = 18 basis points a year, leaving 82 basis points of the spread as compensation for risk and illiquidity.
What a widening costs. The bond's spread duration is 4.28. If the spread widens by one percentage point to 200 basis points while government yields stay put, the duration estimate is a loss of 4.28 percent; repricing the bond at 6.40 percent gives an actual loss of 4.17 percent.
How much widening the carry absorbs. Over one year the bond earns its 100 basis point spread. At the end of the year its duration has fallen to 3.51, so a widening of about 100 / 3.51 ≈ 28 basis points would wipe out the year's extra income.
The panel on this page shows the latest daily readings of investment-grade and high-yield option-adjusted spreads from FRED. It labels high-yield spreads below 3 percent as tight, 3 to 5 percent as normal, 5 to 8 percent as stressed and above 8 percent as distressed, and investment-grade spreads below 1 percent as tight, 1 to 1.7 percent as normal and above that as wide.
When It Applies (and Limitations)
Spread is not expected return. The spread must cover expected default losses before it adds anything. A high-yield spread that looks generous can be fully consumed by defaults in a downturn.
Downgrades cost money before defaults do. A bond can lose value without its issuer ever defaulting, simply because a downgrade moves it into a wider spread bracket. The boundary between investment grade and high yield matters most: many mandates may hold only investment-grade debt, so fallen angels can face forced selling and spread jumps larger than the change in credit quality alone would explain.
Benchmarks differ. Spreads over government bonds and over swap rates are not the same number, and the gap between the two moves with funding conditions.
Liquidity distorts quotes. Many corporate bonds trade rarely. Quoted spreads for illiquid issues can lag the market, especially in stress, when the liquidity premium itself widens.
Embedded options. For callable bonds the raw spread overstates compensation, because part of it pays for the issuer's call option; the option-adjusted spread corrects for that.
Why It Matters for Institutional Investors
The core credit decision. For corporate bonds, high yield or private debt, the spread is the return paid for taking credit risk. Judging whether it covers the default outlook with room to spare is the central act of credit investing.
A macro indicator. Gilchrist and Zakrajšek (2012) show that the excess bond premium, the part of spreads not explained by default risk, predicts economic activity. Spread levels feed most macro regime frameworks.
Sizing and breakevens. Spread duration and breakeven widening translate a spread view into the move that would erase a year's carry, a more useful risk figure than the spread level alone.
Relative value. The gap between a bond's spread and the equivalent credit default swap spread, the basis, is itself traded, and default swaps allow credit exposure to be hedged or added without buying the bond.
References
- Elton, E. J., Gruber, M. J., Agrawal, D., & Mann, C. (2001). Explaining the Rate Spread on Corporate Bonds. Journal of Finance, 56(1), 247-277.
- Huang, J.-Z., & Huang, M. (2012). How Much of the Corporate-Treasury Yield Spread Is Due to Credit Risk? Review of Asset Pricing Studies, 2(2), 153-202.
- Longstaff, F. A., Mithal, S., & Neis, E. (2005). Corporate Yield Spreads: Default Risk or Liquidity? New Evidence from the Credit Default Swap Market. Journal of Finance, 60(5), 2213-2253.
- Gilchrist, S., & Zakrajšek, E. (2012). Credit Spreads and Business Cycle Fluctuations. American Economic Review, 102(4), 1692-1720.
- Duffie, D., & Singleton, K. J. (2003). Credit Risk: Pricing, Measurement, and Management. Princeton University Press.
Frequently asked questions
What is a credit spread in simple terms?
The extra yield a company or other risky borrower pays over a safe government bond of the same maturity. It compensates investors for the chance of default, the loss they would take if it happened and the lower liquidity of the bond. A spread of 100 basis points means the bond yields one percentage point more than the matched government bond.
Why is the spread more important than the bond's yield?
Because the yield mixes two risks. A corporate bond's yield can rise simply because government yields rose, which is interest-rate risk. The spread isolates the credit component, so only a change in the spread shows that the market is repricing the issuer or its appetite for credit risk.
What is the option-adjusted spread?
The spread over the risk-free curve after removing the value of options embedded in the bond, such as a call feature or mortgage prepayment. It lets bonds with and without embedded options be compared on a like-for-like basis and is the standard measure for callable bonds, mortgage-backed securities and credit indices.
Why do credit spreads widen in a recession?
Expected defaults rise, investors demand more compensation for bearing credit risk and many sell less liquid bonds at the same time. All three push spreads wider. Gilchrist and Zakrajšek (2012) show that the part of spreads not explained by default risk is a strong predictor of economic activity.
Do tight spreads mean credit is safe?
No. Spreads tend to be tightest late in an expansion, when compensation for risk is lowest. Buying credit at very tight spreads earns little carry and leaves the investor exposed to a large loss when spreads widen, so tightness is a reason for caution rather than comfort.
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