Original practice · fully worked
Original variant: flat yield required for a target duration with fixed zero faces
A one-year zero-coupon bond has face 20,000 and a five-year zero has face 60,000. Under a flat annual yield, the two-bond portfolio must have Macaulay duration 3 years. Calculate the annual effective yield.
- A
25.29% - B
26.87% - C
28.45% - D
30.03% - E
31.61%
Answer and calculation
Duration 3 requires equal present values in the one- and five-year positions. Equating their discounted faces gives the fourth power of 1 + i equal to 3, so yield 31.61%, choice E.
Setup
Setup
A duration midway between years 1 and 5 requires equal market-value weights.
P1+P5P1+5P5=3 Model
Model
Equate the discounted face amounts under the flat yield.
1+i20000=(1+i)560000 Compute
Compute
Thus the fourth power of 1 + i is 3, giving yield 31.607401%.
(1+i)4=3 i=0.3160740130 Answer
Answer
The annual effective yield is 31.61%, selecting choice E.
i≈31.61%(E)