Inputs |
|
---|---|
Fund Returns |
Base Return Fund |
Index Returns |
Base Return Index |
Weights |
Base Weight Fund |
Fund Returns |
Accret Amort Return Fund |
Fund Contributions |
Base Contribution Fund |
Index Returns |
Accret Amort Return Index |
Index Contributions |
Base Contribution Index |
Relative Returns |
Accret Amort Return Difference |
Attribution Effects |
Allocation |
Smoothed Attribution Effects |
Smoothed Allocation Interaction |
Weights |
Average Base Weight Difference |
About Key Rate Durations
Duration of a bond is the sensitivity of an instrument's value to interest rate changes across the yield curve. It does not capture the impact of yield change at a particular point on the curve. Key rate duration (KRD) is the interest rate sensitivity of the bond's value to interest rate change at a particular point on the yield curve.
Mathematically, the sum of the key rate duration is equal to the duration of the bond. Eagle supports an extension of its Fixed Income Attribution model to support key rate duration decomposition so that the duration matched risk-free price return is decomposed into roll and a set of key rate durations effects.
To quantify the yield curve sensitivity of each bond in a portfolio, you can define a series of key rate durations relative to specific yield curve points. The key rate duration is the percentage price response per 100 basis point movement in a particular risk-free rate ─ while the rest of the yield curve remains constant. By defining many points along the yield curve, key rate durations provide an accurate representation of the sensitivity of each bond in a portfolio to changes of the yield curve.
Key rate durations can play a key role in portfolio management by quantifying the exposure of a portfolio to each section of the yield curve. Using these measures, portfolio managers who deliberately want to express a view about yield curve reshaping structure their portfolio to have different key rate duration exposures from those of their benchmark. Alternatively, investors who want to immunize their portfolios to yield curve reshaping structure a portfolio with the same key rate duration exposures as their benchmark.
To calculate each of the key rate duration returns, you multiply the observed yield change at each of the key rate duration points by -1 times the key rate duration of that point. The following table lists the return for key rate durationi.
Return |
Formula |
Description |
---|---|---|
Key Rate Durationi |
( – (OADiBeg * YieldChgDuri) ) |
The sum of the reshape and parallel decomposition factors is equal to the sum of all of the key rate return factors. |
Where
OAD = effective duration (standard or option adjusted)
i = ith of n key rates
For Key Rate Duration (KRD) analysis, Eagle calculates an average yield change of the curve weighted by the key rate duration points. The average yield change is used instead of pivot point yield change to calculate price return due to parallel shift and reshape. The sum of KRD effects is equal to the sum of the Parallel and Reshape effects. For more information about parallel shift and reshape, see Portfolio and Benchmark Return Decomposition.
Edit the Default Number of Key Rate Durations
You can have as many key rate durations as you like. The default number is 10. Performance System Parameter 11 allows you to edit the default number.
To edit the default number of key rate durations:
- From any Eagle window, click the Eagle Navigator button to access the Eagle Navigator.
- Enter System in the Start Search text box and click the System Parameter (Performance Center) link.
You see the Performance Center and the Performance System Parameters workspace.
Performance System Parameters Workspace
- Select Sys Item 11, Maximum number of Key Rate Duration points for Fixed Income Attribution, right click and select Edit.
You see the Edit Performance System Parameter 11 dialog box.
Edit Performance System Parameter 11 Dialog Box.
- Edit the value in the Item Value text box and click Save.
Specify Optional Fields Such as Par Value, Coupon, and Convexity
You can use the Optional Fields tab on the Creating Fixed Income Options & Field Map Field dialog box to specify additional fields. These additional fields are optional. That is, they are not required for the standard portfolio and benchmark return decomposition that is used for the benchmark relative attribution analysis. See the following figure.
Creating Fixed Income Options & Field Map Field – Optional Fields Tab
The following table describes each option.
Option |
Description |
---|---|
Portfolio |
|
Par Value |
The nominal or face value of the portfolio's bond. |
Coupon |
The interest rate paid by the bond in percent. |
Convexity |
The effective convexity of the bond. For a bond:
|
Local Market Value |
The local market price of the portfolio's bond. |
Benchmark |
|
Par Value |
The nominal or face value of the benchmark's bond. |
Coupon |
The interest rate paid by the bond in percent. |
Convexity |
The effective convexity of the bond. For a bond:
|
Local Market Value |
The local market price of the benchmark's bond. |
Additional Return Decompositions
You can calculate additional bond return components using the Optional Fields tabs on the Creating Fixed Income Options & Field Map Field dialog box. These additional components are return decomposition outputs. They are not currently available as relative return attribution effects.
Total Return Decomposition |
|
---|---|
Currency Return |
((1+ RBase) / (1 + RLocal)) - 1 |
Currency Cross Product |
RLocal * RCurrency |
Local Yield Return |
( 1 + OAYield Begin / 2) ^ (2 * Days in Period / Days In Year) - 1 |
Local Price Return |
( - (OAD Begin * OAYield Change)) |
Yield Return Decomposition |
|
---|---|
Coupon |
= (Coupon Begin * (Days in Period/Days In Year)) / (Market Value Local Begin / Par Value Begin) |
Accretion or Amortization |
= RYield Local – Coupon |
Price Return Convexity Decomposition |
|
---|---|
Return due to Convexity |
(OAC Begin * (OAYield Change) ^ 2) / 2 |
Return excluding Convexity |
RPrice Local + Return due to Convexity |
Convexity can be added as a second term to duration that more precisely evaluates a bond's sensitivity to changes in yield. Convexity is the measure of how much a bond's price/yield curve deviates from a straight line (measure of the degree of curvature of the price/yield relationship at the price/yield point). Convexity used with duration provides a more accurate approximation of the percentage price change.
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