Book 4_Fixed_READING 61_CURVE-BASED AND EMPIRICAL FIXED-INCOME RISK MEASURES Flashcards
Because bonds with embedded options have uncertain cash flows, they do not have a single well-defined yield
Therefore, effective duration and effective convexity must be calculated with respect to shifts in the benchmark curve rather than the bond’s yield for bonds with embedded options.
Effective duration
is a linear estimate of the percentage change in a bond’s price that would result from a 1% change in the benchmark yield curve:
- Effective duration = (V_ - V+)/ (2Vo x ∆Curve)
Effective convexity
= (V_ + V+ - 2Vo)/(Vo x ∆Curve^2 )
Callable bonds and MBS
may exhibit negative convexity at low yields
The expected price change for a bond with respect to an expected ∆Curve
Change in full bond price = -EffDur x (∆Curve) + 1/2 x EffCox x (∆Curve)^2
Key rate duration
is a measure of the price sensitivity of a bond or a bond portfolio to a change in yield for a specific maturity while other yields remain the same
The key rate duration of a cash flow in a portfolio
- The cash flow’s modified duration multiplied by its weight in the portfolio
= modified duration x weight - The effect on the overall portfolio is the sum of these individual effects
analytical durations
The duration measures we have introduced so far, based on mathematical analysis
Macaulay, modified, and effective duration
are examples of analytical duration
Empirical duration
- is estimated from historical data using models.
- may be lower than analytical duration in interest rate environments where the assumptions underlying analytical duration may not hold, such as for credit risky bonds in a flight-to-quality scenario