The credit spread on the lowest-rated U.S. corporate bonds, those rated CCC or below, jumped 2.21 percentage points in a month, from 10.76 percentage points on Sept. 16, 2026 to 12.97 percentage points on Oct. 16. Over the same period, the spread on high-quality (investment-grade) corporate bonds barely moved, from 0.78 to 0.85 percentage points.
A credit spread is the extra interest a corporate bond pays over a U.S. Treasury bond of the same maturity. When the gap widens, it means the market is demanding more compensation for risk, and the price of that company's existing bonds falls.
A jump in corporate bond yields is often read as a sign that a recession is coming and every company is in danger. But the key point is elsewhere. This time, only the bottom rung has opened up sharply. The market is not worrying about the whole economy. It is picking out the weakest companies first, the ones that will struggle to withstand high interest rates.
- A credit spread is the price of the risk of not being repaid
U.S. Treasury bonds are debt owed by the U.S. government, so they serve as the benchmark with the least risk of default. A company has to pay more interest than the Treasury to borrow, and that extra payment is the credit spread.
A credit rating (a grade from a rating agency on how able a borrower is to repay its debt) of BBB or higher is investment grade, and anything below that is speculative grade. Speculative-grade bonds are called high-yield bonds, or more commonly junk bonds. CCC and below is the bottom rung even within speculative grade.
Think of it like a bank loan. The lower a person's credit score, the higher the interest rate on the same loan. If you lent KRW 10 million for a year, then as of Oct. 16 a company rated CCC or below would have to pay about KRW 1.3 million more than the Treasury, while a high-quality company would pay about KRW 85,000 more (a simple hypothetical calculation).
- Over the month, the lower the rating, the wider the spread got
| Rating | Sept. 16 | Oct. 16 | Change |
|---|---|---|---|
| All investment grade | 0.78 pp | 0.85 pp | +0.07 pp |
| BBB | 0.96 pp | 1.06 pp | +0.10 pp |
| BB | 1.55 pp | 2.03 pp | +0.48 pp |
| B | 2.78 pp | 3.35 pp | +0.57 pp |
| CCC and below | 10.76 pp | 12.97 pp | +2.21 pp |
| All speculative grade | 2.70 pp | 3.31 pp | +0.61 pp |
BBB, the bottom of investment grade, rose only 0.10 percentage points, while BB and B, in the upper part of speculative grade, rose 0.48 to 0.57 percentage points.
Put simply, the further down the ladder, the bigger the rise. The jump at the very bottom was about four times that of B just above it and more than 30 times that of high-grade bonds.
- The 3.31-point speculative-grade average hides the bottom rung
The credit spread for all speculative-grade bonds, the figure often cited in the news, rose 0.61 percentage points over the same period, from 2.70 to 3.31 percentage points.
An average blends the moves of several rungs. Even if the bottom rung jumps, the average rises less if the upper rungs move less. It is like looking only at a class's average score and not knowing how many students failed a test badly. One difference, though: unlike a class average, this average gives more weight to bonds with a larger amount outstanding.
- Bottom-rung companies must refinance cheap debt at a high price
In an Oct. 15 report, Jackie Rogowitz, an analyst at U.S. asset manager Penn Mutual Asset Management, pointed out that many CCC-rated companies have relied on money borrowed in 2020-2021, when interest rates were low. When that debt comes due, they have to borrow again at today's rates to pay it off. The U.S. 10-year Treasury yield was 5.09% on Oct. 16.
With a large extra payment stacked on top of Treasury yields above 5%, the yield on CCC-and-below corporate bonds as a whole (the annual interest rate you would earn if you bought now and held to maturity with no default) reached 17.66% on the same day. Rogowitz said these companies have little financial cushion and weak free cash flow (the cash left over after spending).
It is like someone who used an overdraft account at a cheap rate, and when they try to extend it, the bank quotes a rate several times higher. Someone with plenty of income can hold on, but someone with a tight budget has fewer ways to repay.
- As high-grade yields rose, the reason to buy the bottom rung shrank
Rogowitz noted that as interest rates have risen, investment-grade bond yields have climbed to nearly 6%, close to their highest level since 2023. The yield on U.S. investment-grade corporate bonds as a whole was 5.86% on Oct. 16.
Even bonds with little default risk now pay close to 6%, and BB-rated bonds carry far lower default risk than CCC while still paying generous interest. There is less reason to buy the bottom-rung bonds. When fewer people want to buy, the bond's price falls and the yield gap widens further. Rogowitz summed it up this way: the market as a whole is stable, but pressure is building at the very bottom of the rating ladder.
- When every company turns risky, high-grade spreads jump too
There have also been times when investment grade and speculative grade jumped together. Between April 2 and 7, 2025, the investment-grade spread rose from 0.96 to 1.20 percentage points, and the speculative-grade spread as a whole rose from 3.42 to 4.61 percentage points. Within days, even high-quality companies were being charged for risk.
This time is different. The investment-grade spread moved only 0.07 percentage points in a month. It does not look like the pattern you see when worry about the whole economy spreads. It looks more like pressure building on the bottom rung.
- BITPRESS Insight
If you own a high-yield fund that holds speculative-grade bonds, what matters more than the average yield gap is which ratings the fund holds and how much of each. Even among high-yield funds, a fund focused on BB bonds and a fund with a large share of CCC are standing in different markets right now.
The same goes for the stocks of heavily indebted companies. As the time to borrow anew and repay old debt draws closer, the growing interest burden may show up in the stock price first.
When you see news that junk bond yields have jumped, the question to ask is not “how much did they rise?” but “which rung is widening?” If only the bottom is widening, it is selection. When the high-quality rungs widen too, that is closer to a signal to worry about the whole economy.
Sources
https://fred.stlouisfed.org/series/BAMLH0A3HYC
https://fred.stlouisfed.org/series/BAMLC0A0CM
https://fred.stlouisfed.org/series/BAMLH0A0HYM2
https://fred.stlouisfed.org/graph/fredgraph.csv?id=BAMLH0A1HYBB,BAMLH0A2HYB,BAMLC0A4CBBB
https://fred.stlouisfed.org/graph/fredgraph.csv?id=DGS10,BAMLC0A0CMEY,BAMLH0A3HYCEY
https://www.pennmutualam.com/market-insights/blogs/chart-of-the-week/2026-10-15-wider-ccc-spreads-signal-growing-stress
Glossary
Credit spread — The extra interest a corporate bond pays over a Treasury bond of the same maturity, which is the price the market puts on the risk of not being repaid by that company.
Investment grade — Bonds rated BBB or higher by a rating agency, issued by companies judged to have a relatively strong ability to repay their debt.
Speculative grade (high yield, junk bonds) — Bonds rated below BBB, which pay more interest in return for a higher risk of default.
Percentage point — The difference between two values expressed as percentages. If a rate rises from 0.78% to 0.85%, it has risen 0.07 percentage points.
Before — The date a borrower has promised to repay a loan. If the money is not there by then, the borrower has to borrow again to pay it off.
BITPRESS articles are information to help your investment decisions, not a recommendation to buy or sell any stock or coin. Investment decisions and their results are your own responsibility.
