Use matrix pricing to value a bond that rarely trades
The idea
Most bonds do not trade on a given day, so their prices must be estimated from bonds that did. Matrix pricing interpolates a yield from comparable issues — similar credit quality, similar sector, bracketing maturities — and then discounts the subject bond's cash flows at that yield. It is also used to set the coupon on a new issue so it prices near par. The method is only as good as the comparability of the bonds chosen, and it silently assumes that the differences between issuers that share a rating are immaterial, which is exactly the assumption credit analysis exists to question.
A practice question
What problem does matrix pricing address?
- That bond coupons change over timeWhy not: A fixed-rate coupon does not change, and a floater's reset is observable. Neither creates the problem matrix pricing solves.
- That many bonds do not trade frequently enough to provide a current market price — correct
- That credit ratings are revised infrequentlyWhy not: Stale ratings are a real limitation, and one matrix pricing inherits rather than fixes. The problem it addresses is the absence of a recent trade.
Without a recent trade there is no observed price. Matrix pricing infers one from comparable bonds that did trade.
A harder one
How is a yield estimated for a bond with a maturity between two traded comparables?
- By interpolating between the yields of the bracketing comparable bonds — correct
- By using the yield of the nearest government bondWhy not: That gives a risk-free benchmark with no credit spread. The comparables are chosen to share the subject's credit quality precisely so the spread comes with them.
- By averaging the coupons of all bonds in the sectorWhy not: Coupons reflect when each bond was issued, not what the market requires now. The estimate has to be built from yields.
Linear interpolation across maturity, holding credit quality and sector constant, is the standard approach and is why the comparables must bracket the subject.
The hardest tier
What does matrix pricing implicitly assume about two issuers sharing a rating?
- That their bonds have the same maturityWhy not: Maturity is handled explicitly, by bracketing and interpolating. It is the one difference the method does not assume away.
- That the differences between them do not matter for yield — correct
- That both will be downgraded togetherWhy not: The assumption concerns how they are priced today, not how their ratings will move.
A rating is a coarse summary, and the assumption that it captures everything is the one credit analysis exists to test.
In the app: 12 practice questions on this outcome, a narrated walkthrough with diagrams, spaced review that brings it back before you forget it.
Take the free diagnostic →