Bond default rates by credit rating follow a steep, nonlinear curve: AAA-rated corporate bonds have defaulted at a ten-year cumulative rate of just 0.81%, while CCC/C-rated bonds have defaulted at more than 55% over the same period, according to S&P Global’s long-running default study.1S&P Global Ratings. S&P Global Ratings Definitions – Section: Long-Term Issue Credit Ratings Each notch down the scale adds more risk than the one before it, and the jump from the lowest investment-grade tier to the highest speculative-grade tier is where the curve bends hardest.
Ten-Year Cumulative Default Rates for Corporate Bonds
S&P Global tracks every rated corporate issuer going back to 1981. The ten-year cumulative default rates from that dataset lay out the pattern:
- AAA: 0.81%
- AA: 0.96%
- A: 1.57%
- BBB: 3.80%
- BB: 12.90%
- B: 24.20%
- CCC/C: 55.70%
Two features of that table shape how bonds are priced and held. First, movement within investment grade is modest: the gap between A and BBB is only about two percentage points over a full decade. Second, the step from BBB (the lowest investment-grade rating) to BB (the highest speculative-grade rating) more than triples the default rate, from 3.80% to 12.90%. That single notch is where institutional mandates and index rules draw their lines, and it’s where the risk curve stops being gentle.
Over shorter time frames, the shape holds but the absolute numbers shrink. Investment-grade bonds as a group carry one-year default probabilities below 0.1%.2Federal Reserve Bank of New York. Understanding Aggregate Default Rates of High Yield Bonds Speculative-grade annual rates run much higher and swing with the economy in ways investment-grade rates don’t.
The Investment-Grade Line
The bond market treats one specific boundary as a hard line: BBB- or above is investment grade; BB+ or below is speculative grade. For Moody’s, the equivalent cutoff is Baa3 versus Ba1.3S&P Global. Understanding Credit Ratings – Section: Ratings Scale4Moody’s Investors Service. Moody’s Rating Scale and Definitions
Many pension funds, insurance companies, and bond index funds are barred from holding speculative-grade debt, either by regulation or by their own guidelines. When a bond gets downgraded from BBB- to BB+, those forced sellers unload, and the price falls even when the issuer’s actual condition has barely changed. The threshold produces a cliff in market pricing that the smooth progression of default probabilities doesn’t explain on its own.
The economic reality behind the labels: investment-grade issuers tend to carry manageable debt, generate stable cash flows, and refinance easily. Speculative-grade issuers often carry high leverage, work in volatile industries, or lack a long track record. The market demands a yield premium, the credit spread, to compensate for that elevated risk, and the spread widens sharply during periods of stress.
Municipal Bonds Default Far Less Often
A credit rating is not an apples-to-apples risk measure across asset classes. S&P Global data through 2024 shows municipal bonds defaulting at a small fraction of the corporate rate at every grade:
- AAA: 0.00% municipal vs. 0.81% corporate
- AA: 0.03% municipal vs. 0.96% corporate
- A: 0.08% municipal vs. 1.57% corporate
- BBB: 0.73% municipal vs. 3.80% corporate
- BB: 4.14% municipal vs. 12.90% corporate
- B: 10.32% municipal vs. 24.20% corporate
- CCC/C: 36.31% municipal vs. 55.70% corporate
A BBB-rated municipal bond has historically defaulted at a lower rate than a AAA-rated corporate bond. State and local governments have taxing authority and essential-service revenue streams that corporations don’t; a city can raise property taxes to cover debt service, while a corporation facing falling revenue has no equivalent lever. If you hold both asset classes, read the letter grades in the context of the sector, not as if they were interchangeable.
What “Default” Means in the Numbers
Rating agencies define default more broadly than a missed payment. A corporate default includes failure to pay principal or interest when due, bankruptcy filings, and distressed exchanges in which bondholders accept a new security worth less than the original.5S&P Global Ratings. S&P Global Ratings Definitions – Section: General-Purpose Credit Ratings A company that persuades creditors to swap a $1,000 bond for one worth $600 has defaulted in the data even though it never filed for bankruptcy.
A separate category, technical default, covers covenant breaches, such as failing to maintain required insurance or breaching a debt ratio, without missing a payment. Technical defaults trigger contractual remedies but don’t always escalate. The published S&P and Moody’s default rates track payment defaults and distressed exchanges, not covenant breaches, so the figures above reflect the more severe outcomes.
Recovery Rates and What You Actually Lose
Default rates tell you how often bonds fail. They don’t tell you how much money you lose when one does. That depends on the recovery rate: how many cents on the dollar bondholders get back after a default, through bankruptcy proceedings, asset liquidation, or a restructured exchange. The economic hit is the loss given default, which is one minus the recovery rate.
Recovery depends heavily on where your bond sits in the issuer’s capital structure. Over the period 1982–2003, Moody’s reported these average recovery rates for defaulted corporate bonds:
- Senior secured: roughly 51–53 cents on the dollar
- Senior unsecured: about 33 cents on the dollar
- Senior subordinated: approximately 39 cents on the dollar over the full period, with sharp year-to-year variation
Senior unsecured bonds, the most common type in institutional portfolios, historically recover about a third of par.6Moody’s Investors Service. Recovery Rates on Defaulted Corporate Bonds and Preferred Stocks If a B-rated bond has a ten-year cumulative default rate around 24% and recovery averages 33 cents, the expected credit loss over that period works out to roughly 16% of par (24% default rate multiplied by 67% loss given default). Expected loss equal to default probability times loss given default is the foundation of how banks set capital requirements and how portfolio managers price credit risk.7Federal Reserve Bank of Chicago. Loss Given Default and Economic Capital
Recovery rates themselves move with the cycle. In healthy economies, distressed assets attract more bidders and recoveries run higher. In recessions, defaults cluster and buyers are scarce, so recoveries fall and losses compound at the worst possible time. High-yield recoveries in 2010 averaged about 57% of par, which was unusually strong because many of those defaults were distressed exchanges rather than full liquidations.
Where Default Rates Stand Now and How Cycles Move Them
Default rates aren’t static. They spike during recessions and compress during expansions, and the effect lands almost entirely on speculative-grade bonds. Investment-grade issuers have the cash reserves and market access to ride out a rough year; speculative-grade issuers, with thinner margins and heavier debt, are the ones that buckle when revenue drops or refinancing dries up.
As of January 2026, the U.S. trailing twelve-month speculative-grade corporate default rate was 3.8%, up slightly from 3.7% at the end of 2025. S&P Global Ratings forecasts a base-case rate of 3.75% by December 2026, with a pessimistic scenario of 4.75% and an optimistic scenario of 2.5%.8S&P Global Ratings. Default, Transition, and Recovery: January Corporate Defaults Almost Entirely U.S.-Based That base case is moderate by historical standards. The speculative-grade default rate climbed above 10% during the 2008–2009 financial crisis and exceeded 12% during the early 2000s downturn. Long-run averages blend calm years and crisis years into a single figure that may not represent either accurately.
Ratings Migrate, Which Is Why Even AAA Shows Some Defaults
Bonds don’t keep the same rating forever. The most watched form of migration is the fallen angel: a bond issued at investment grade and later downgraded to speculative grade. Fallen angel status isn’t a death sentence. Over a twenty-year observation period, Moody’s found that nearly a quarter of fallen angels climbed back to investment grade, about half stayed in speculative territory without defaulting, and roughly 12% eventually defaulted.9European Central Bank. Understanding What Happens When “Angels Fall” That 12% is below the overall speculative-grade rate, partly because fallen angels were once strong enough to earn an investment-grade rating and often retain some of that underlying resilience.
Migration also works upward. Rising stars are speculative-grade issuers upgraded to investment grade, which lowers their borrowing costs and widens their investor base. The practical point for bondholders: a current rating is a snapshot. The cumulative default rates by rating category already fold migration in, because an issuer rated BBB at the start of a ten-year window that gets downgraded to B before defaulting still counts as a BBB default in that cohort. That’s why even AAA shows a nonzero ten-year default rate. A handful of issuers rated AAA at the start of the window drifted down through multiple downgrades before eventually failing.