Key Rate Duration
Key Rate Duration (KRD) measures a bond's or portfolio's price sensitivity to a 100 basis point change in the yield at a specific maturity point along the yield curve — such as the 2-year, 5-year, or 10-year rate — while holding other maturities constant, enabling granular analysis of exposure to non-parallel shifts in the yield curve.
Traditional modified duration measures a bond's price sensitivity to a parallel shift in the entire yield curve — every maturity moves by the same number of basis points simultaneously. In practice, yield curves rarely shift in perfect parallel. The Reserve Bank of India's monetary policy actions, liquidity conditions, fiscal borrowing announcements, and global risk factors cause different parts of the yield curve to move independently. A short-end rate change driven by RBI repo rate decisions affects the 1-2 year segment more than the 10-year segment; a large government borrowing announcement that causes fiscal concerns primarily affects the long end; foreign portfolio investor (FPI) activity in specific maturity buckets creates localised yield movements. Key Rate Duration captures these non-parallel shift risks by measuring sensitivity at multiple specific points on the curve.
The standard key rate duration framework uses maturities at 0.25, 0.5, 1, 2, 3, 5, 7, 10, 20, and 30 years. The KRD at each maturity node measures price impact if only that node's yield moves by 1% (100 bps) while all other nodes remain unchanged. The sum of all KRDs equals the bond's modified duration, providing a useful consistency check. A bullet bond with a 10-year maturity will have its KRD concentrated at the 10-year node; a bond with serial coupon payments will have KRD distributed across multiple nodes proportional to the present value contribution of each cash flow.
For Indian government bond portfolio management, KRD analysis is particularly relevant given the active management of the yield curve by RBI through Open Market Operations (OMOs), Operation Twist, and the Government Securities Acquisition Programme (GSAP). During Operation Twist — where RBI simultaneously sold short-duration bonds and purchased long-duration bonds to flatten the yield curve — portfolio managers with detailed KRD positions at the short and long ends were better positioned to assess and hedge their exposure than those relying solely on aggregate modified duration.
Gilt mutual funds and dynamic bond funds in India that actively manage duration across the yield curve maintain KRD profiles as part of their internal risk management. The portfolio manager's view on the yield curve shape — whether expecting a steepening, flattening, or humped curve — informs position sizing at specific maturity nodes to maximise expected return while managing KRD concentration. For instance, a fund manager expecting a steepening yield curve (short rates falling more than long rates) would position to have higher positive KRD at the short end and potentially lower or even negative KRD at the long end through futures hedging.
From a retail investor's perspective, KRD is most relevant when evaluating debt mutual funds with specific maturity profiles — a short-duration fund should have its KRD concentrated at the 1-3 year nodes, while a long-duration gilt fund will have the bulk of its KRD at the 10-30 year nodes. A mismatch between the fund's stated category (e.g., medium duration) and its KRD profile (concentrated at 10+ years) would indicate that the fund manager is taking duration risk beyond what the category mandate implies.