What Is Coupon Yield?
Coupon yield is the fixed annual interest a bond pays, expressed as a percentage of its face value and set at the moment of issue. The payment never changes for the life of the bond, which is why the coupon and the market yield diverge from the first day of trading.
A bond has exactly one number that is fixed for its entire life. Understanding which one it is makes the other three yields people quote stop being confusing.
How it works
The coupon is set when the bond is issued and never changes. A bond with a face value of 1,000 and a 5% coupon pays 50 a year, every year, until it matures. Not 5% of the market price — 5% of face value, in cash.
So the coupon rate and the market yield separate immediately. The day after issue the bond trades at some price, and every yield measure divides that same fixed 50 by a number that moves.
They coincide at exactly one price. At par — market price equal to face value — coupon rate, current yield and yield to maturity are all the same figure. Anywhere else, all three differ.
It is a promise, not a policy
This is the sharpest difference from a dividend. A company chooses whether to pay a dividend and can reduce it in a bad year with no legal consequence. A coupon is a contractual obligation.
Missing one is a default. That triggers consequences a dividend cut never does, which is the whole reason bondholders rank above shareholders and accept a lower expected return for it.
A worked example
A thirty-year bond with a 4% coupon, issued at 1,000. It pays 40 a year for thirty years, then returns the 1,000.
Year one: 40 buys what 40 buys. By year thirty it is the same 40 in cash against three decades of prices.
At 3% inflation, purchasing power falls to about 41% over thirty years — which inflation works through. So the final coupon buys well under half what the first one did, while the number on the payment stays identical.
And the 1,000 returned at the end is the same nominal 1,000 you lent. In real terms it is a fraction of what you handed over. That is the fundamental trade in long fixed-rate lending, and the coupon is the compensation being offered for it.
Why issuers pick the coupon they pick
The coupon is set so the bond sells at or near face value on day one. If the market wants 4% for that issuer over that period, the coupon is set at roughly 4% and the bond prices around par.
Everything afterwards is the market repricing. The issuer never revisits the coupon; the price does all the adjusting, which is why a bond issued at 4% in a 4% world trades well below par in a 7% one.
A higher coupon buys something. Issuers offer above-market coupons when they want a specific feature in return — most commonly the right to repay early, which is what a callable bond is. The extra income is the price of that right, paid to you.
And a zero coupon is the other extreme. No payments at all, sold at a deep discount, with the entire return arriving at maturity. It carries the longest duration of any bond of the same maturity, because none of the money comes back early.
The original data
Use this site’s thirty-year fee measurement to price what small annual percentages do: 5 basis points costs 1.5% of the final balance, 20 costs 5.8%, 75 costs 20.2%, 150 costs 36.5%.
Inflation runs the same arithmetic at a far larger number. Three percent a year is 300 basis points — double the largest figure in that table — and it is charged against every fixed coupon for the whole life of the bond. The coupon does not adjust; only its buying power does.
And reinvesting each coupon costs a round trip — 0.0098 on this site’s shared series, about 2% of the median bar range of 0.493, paid every time a payment is put back to work.
One further consequence: the coupon decides how much of your return arrives early. A high-coupon bond hands back most of its value along the way; a low-coupon one leaves it at the end. That changes the reinvestment problem, the duration, and how exposed the holding is to the issuer surviving — three different risks all set by one number chosen at issue.
When it fails
The characteristic failure is choosing a bond by its coupon. A 7% coupon reads as better than a 4% one, and it says nothing about what you pay for it. A 7% bond trading at 130 can deliver a lower return than a 4% bond trading at 90, because the capital movement at redemption runs the other way. The coupon is an input to the return, not the return, and it is the input most visible on a listing.
A second failure is assuming a fixed coupon is a fixed income. It is fixed in cash and shrinking in purchasing power every year.
A third is comparing a coupon to a dividend yield — one is contractual, the other discretionary, and they are not the same kind of promise.
A fourth is forgetting accrued interest. Buy between payment dates and you pay the seller for the part of the coupon they earned.
And a fifth is reading a zero-coupon bond as paying nothing. It pays everything at the end, sold at a discount instead — same idea, no intermediate cash.
A last practical note. Coupons are usually paid twice a year rather than annually, so a 5% coupon arrives as two payments of 2.5% of face value. That detail matters for reinvestment timing and for the accrued interest you pay when buying between dates.
Related
Current yield covers the coupon divided by today’s price. Yield to maturity covers the full return including the capital. And inflation covers what a fixed payment is worth thirty years out.
The coupon is the one number in a bond that never moves, which makes it the anchor for understanding everything that does. Every other yield you will see quoted is that same fixed payment divided by something that changed.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.