What Are Credit Spreads and What Do They Tell Us About Risk?

While stock market headlines dominate the news, some of the most important signals about economic health come from the bond market. Credit spreads (the difference in yield between corporate bonds and "risk-free" government bonds) are one of the bond market's most powerful risk indicators. When spreads widen, it often means trouble is brewing beneath the surface.

What Are Credit Spreads?

When a corporation issues a bond, it must pay a higher interest rate than the government because there is a risk the company could default. The difference between the corporate bond yield and the government bond yield of the same maturity is called the credit spread.

For example, if a 10-year US Treasury bond yields 4.0% and a 10-year investment-grade corporate bond yields 5.2%, the credit spread is 1.2 percentage points (or 120 basis points). This spread represents the premium that investors demand for bearing the additional risk of lending to a corporation rather than the US government.

Credit spreads are typically expressed in basis points (bps), where 1 basis point = 0.01%. A spread of 150 bps means the corporate bond yields 1.50 percentage points more than the comparable government bond.

Why Do Spreads Widen and Narrow?

Credit spreads fluctuate based on how investors perceive risk in the economy:

• Narrow spreads (low risk appetite): When the economy is healthy and default risk is perceived as low, investors are willing to accept a smaller premium for corporate bonds. Spreads compress. This typically occurs during economic expansions and bull markets.
• Widening spreads (rising fear): When investors become worried about economic slowdown, rising defaults, or financial system stress, they demand a larger premium for holding corporate bonds. They may also sell corporate bonds and flee to the safety of government bonds, pushing yields in opposite directions and widening the spread further.

This makes credit spreads a real-time gauge of fear in the financial system. Unlike lagging indicators such as unemployment, credit spreads react immediately to changing perceptions of risk.

Types of Credit Spreads

Not all credit spreads are created equal. The two most commonly tracked categories are:

Investment-Grade (IG) Spreads

These measure the premium on bonds rated BBB- or higher by rating agencies. Investment-grade bonds are issued by large, financially stable companies. IG spreads tend to be relatively narrow (50–200 bps in normal conditions) and widen modestly during stress.

High-Yield (HY) Spreads

Also known as "junk bond" spreads, these cover bonds rated below investment grade. High-yield spreads are more volatile and sensitive to economic conditions, often ranging from 300 bps in good times to over 1,000 bps during crises. HY spreads are particularly useful for detecting credit market stress early.

Crash Gauge tracks investment-grade credit spreads for the US dashboard, using the difference between the US Treasury High Quality Market (HQM) Corporate Bond 10-year par yield and the 10-year Treasury Constant Maturity rate. Both series are freely available from FRED.

Credit Spreads as a Crash Indicator

The historical record shows that credit spread spikes have accompanied or preceded every major market downturn:

• 2000–2002: IG spreads widened gradually through 2001 as the dot-com bust exposed over-leveraged telecom and energy companies (Enron, WorldCom).
• 2007–2009: Credit spreads began widening in mid-2007 and exploded to multi-decade highs in late 2008 as the financial system nearly collapsed. IG spreads exceeded 600 bps, a level not seen since the Great Depression.
• 2020: Spreads spiked violently in March 2020 as pandemic fears gripped markets, but normalised quickly after the Federal Reserve announced it would purchase corporate bonds for the first time in its history.

The speed and magnitude of credit spread moves often tell you more about the severity of a crisis than stock prices alone. A stock market dip with stable credit spreads is usually a routine correction. A stock market dip accompanied by rapidly widening credit spreads is a much more serious signal.

How Crash Gauge Uses Credit Spreads

On the US Crash Risk Dashboard, the investment-grade credit spread is one of the highest-weighted indicators:

1. The current IG spread is calculated from FRED data (HQM 10-year corporate par yield minus 10-year Treasury rate).
2. This spread is ranked against approximately 30 years of historical data to produce a percentile. A wide spread puts the reading in a high percentile, directly translating to high risk.
3. The percentile feeds into the weighted composite alongside the yield curve, CAPE, and other indicators. Credit spreads receive a high weight because of their strong empirical association with financial crises.

Key Takeaways

• Credit spreads measure the premium investors demand for corporate bonds over government bonds.
• Narrow spreads signal confidence; widening spreads signal rising fear and perceived default risk.
• Spreads react in real time to changing risk perceptions, making them a leading indicator rather than a lagging one.
• Major credit spread spikes have accompanied every significant market crisis in modern history.
• Crash Gauge tracks US investment-grade credit spreads as one of its highest-weighted indicators, ranking the current level against 30 years of history.

Credit spreads may not grab headlines the way stock prices do, but they are arguably a more honest barometer of financial system health. When corporate borrowing costs spike relative to government rates, it's a signal that the market's collective judgement about risk has shifted. Combined with the other indicators on Crash Gauge, credit spreads help provide an early-warning system grounded in real bond market data.

For more on how all 14 indicators are combined, see our Methodology page.