What it means
A yield curve contains rates for different maturities, not one universal interest rate. A central-bank announcement can affect short yields strongly while longer yields change less or move in the opposite direction, and a single parallel-shift duration can miss this pattern.
Key rate duration asks a narrower question: how would the modelled price respond if one selected benchmark maturity moved? Analysts change the relevant curve location, reprice the instrument, and compare the new prices with the original, and the method must specify how nearby maturities are treated.
The output is usually a collection of sensitivities, for example separate two-year, five-year, and ten-year exposures for one portfolio. A five-year sensitivity describes responsiveness at that curve location, not the bond's maturity.
Payments due at different dates create exposure across several key rates, and embedded options can change expected cash flows, which requires suitable repricing. The CFA Institute describes key rate duration as partial duration and distinguishes it from a curve-wide measure.
Under a consistent curve-shift framework, the collection helps explain overall effective duration. The number of selected points is a modelling choice, not a universal requirement that every analysis contain eleven maturities.
Two portfolios with similar overall duration can have different key-rate profiles. One can concentrate exposure in intermediate maturities while another combines short and long exposures, so they may respond similarly to a parallel shift but differently to a steepening or flattening curve.
The measure does not forecast which yields will move; analysts combine it with explicitly defined scenarios to estimate possible price changes. An attractive scenario result does not establish that the forecast will occur or that a hedge will perform exactly as modelled.
A duration estimate is an approximation, especially for larger movements or instruments with changing cash flows, and convexity, option behaviour, interactions among curve points and credit spreads need separate analysis because a benchmark-rate sensitivity is not a complete loss measure. For non-finance managers, request the curve-point assumptions alongside the headline duration, because matching one overall number may leave a pension, treasury portfolio, or funding arrangement exposed when different maturities move unevenly.
In practice
Real-world examples.
Example
A fictional treasurer compares two portfolios with similar total duration. Their five-year key rate sensitivities differ substantially, so the team tests an intermediate-maturity shock rather than assuming the portfolios have identical interest-rate risk.
Example
A pension analyst compares asset and liability sensitivities at the same benchmark maturities. Matching the total alone leaves a ten-year mismatch, which becomes visible when the analyst models a curve change concentrated at that point.
Example
A manager sees losses after benchmark yields and credit spreads rise together. The risk report separates the key-rate estimate from spread effects instead of attributing every price change to the yield curve.
Formula
Calculation
A central-difference estimate is KRD = (price after a local downward shift - price after a local upward shift) / (2 x shift size x original price). The yield shift is expressed as a decimal and applied consistently to the selected curve point.
Assume price 100, downward-shift price 100.30, upward-shift price 99.70, and a 0.001 shift. KRD = 0.60 / (2 x 0.001 x 100) = 3.0.
For a small upward shift of 0.002 at that point, estimated price change is -3.0 x 0.002 = -0.6%, with other modelled factors unchanged. Actual repricing can differ.Case study
Seen in the real world.
In this fictional case, Riverbend Services holds bonds against a future project payment. The director assumes matching total duration eliminates interest-rate exposure. Treasury produces a key-rate profile and discovers that the assets and projected funding requirement respond differently around intermediate maturities. The team uses common curve points and consistent assumptions before comparing the two profiles.
The director keeps the mismatch visible in the project-risk report. Treasury tests several curve shapes and reviews cash needs before proposing any portfolio change. The case demonstrates better diagnosis of exposure, not a guarantee that a particular trade removes every funding risk.
Watch out
Common mistakes.
- Assuming portfolios with the same total duration respond identically to nonparallel yield-curve changes.
- Comparing key-rate figures produced from different curve points or shift methods without reconciling their assumptions.
- Treating benchmark-rate sensitivity as a forecast or as complete coverage of credit, liquidity, and option risk.
Questions
People also ask.
Is key rate duration simply the bond's maturity?
No. It measures price sensitivity to a selected benchmark maturity. A bond can have exposure to several curve locations because of its payments and pricing structure.
Must every analysis use eleven key rates?
No. Analysts choose relevant curve points and a consistent method. The selected structure determines how the sensitivities describe the instrument or portfolio.
Does matching total duration remove every curve risk?
No. Similar totals can conceal different maturity profiles. Nonparallel shifts can expose mismatches that a single parallel-shift summary does not show.
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