What it means
Ratings agencies divide the bond universe at a single line. Anything rated BBB- or better by Standard and Poor's and Fitch, or Baa3 or better by Moody's, is investment grade; anything below is speculative grade, commonly called high yield or junk.
That line matters far more than one notch of credit quality should, because many pension funds, insurers and mandates are contractually barred from holding sub-investment-grade paper. Crossing the line therefore triggers forced selling or forced buying, not just a repricing.
An angel bond is simply a bond sitting comfortably on the safe side of that line. Issuers work hard to stay there because investment grade status widens the pool of buyers, lowers the coupon they must offer and reduces the covenants lenders demand.
The pricing logic is straightforward: yield equals a risk-free government yield plus a credit spread. A stronger rating means a narrower spread, and because bond prices move inversely to yields, a ratings upgrade that narrows the spread pushes the price up.
The related terms are worth keeping straight. A fallen angel has dropped from investment grade to junk, a rising star has climbed the other way, and an angel bond is one that is investment grade right now regardless of which direction it travelled to get there.
The label says nothing about the return an investor will earn from here. An angel bond bought at a rich price when yields are low can still deliver a poor outcome, because credit quality and value are separate questions that need judging on their own.
In practice
Real-world examples.
Example
A utility issues $400,000,000 of 10-year bonds rated A-. Because the paper is investment grade, insurance companies and pension funds can buy it, and the coupon comes in around 200 basis points below what a comparable high yield issuer would pay.
Example
A retailer downgraded during a difficult period sells assets, cuts debt and is restored to BBB-. Index funds tracking investment grade benchmarks become forced buyers, and the bonds rally ahead of the formal upgrade as the market anticipates it.
Example
A treasurer refuses a leveraged acquisition that would add $600,000,000 of debt, because losing investment grade status would raise the cost of the company's entire $2,000,000,000 debt stack rather than only the new borrowing.
Formula
Calculation
Approximate price change = -modified duration x change in yield
A corporate bond rated BB yields 7.2%. The issuer completes a deleveraging plan, the agencies upgrade it to BBB, and the credit spread narrows by 150 basis points, taking the yield to 7.2% - 1.5% = 5.7%. It is now an angel bond.
The bond has a modified duration of 6.0, so the approximate price move is -6.0 x -1.5% = +9.0%.
If the bond was trading at $960 per $1,000 of face value, the new price is roughly $960 x 1.09 = $1,046.40, a gain of about $86.40 per bond before any coupon income. On a $5,000,000 holding, that upgrade is worth in the region of $450,000 of mark-to-market value.Case study
Seen in the real world.
The following is an illustrative and entirely fictional case. Corvane Water Utilities, an invented infrastructure business, had been rated BB after a debt-funded expansion and its bonds yielded 7.2%, trading at $960 per $1,000 of face value.
The fictional management team sold a non-core division, used the proceeds to cut net debt, and committed publicly to a leverage target. Eighteen months later two agencies moved the rating to BBB, and the credit spread narrowed by 150 basis points to a 5.7% yield. With a modified duration of 6.0, the price rose roughly 9% to about $1,046.40.
Two effects followed. Existing holders gained around $86.40 per bond in mark-to-market value, and the company found its next $300,000,000 issue attracted insurers and pension funds that had previously been unable to participate, which cut the coupon it had to offer and paid back the cost of the restructuring within a few years.
Watch out
Common mistakes.
- Assuming an angel bond is risk free, when investment grade means low default risk rather than none.
- Mixing up angel bonds with fallen angels, which are the opposite case of a bond that has dropped out of investment grade.
- Ignoring interest rate risk because the credit looks safe, since a long-dated high grade bond can still lose value sharply when yields rise.
Questions
People also ask.
Where exactly is the investment grade line?
At BBB- for Standard and Poor's and Fitch, and Baa3 for Moody's, with anything below counted as high yield.
Why do issuers care so much about staying above it?
Because it determines who is allowed to buy their debt, and a wider buyer pool means a lower coupon and lighter covenants.
Is a higher rating always worth the cost of achieving it?
Not necessarily, since holding less debt to protect a rating can mean forgoing investments that would earn more than the interest saved.
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