In: Finance
Consider a five-year, 8 percent annual coupon bond selling at
par of $1,000.
a. What is the duration of this bond?
b. If interest rates increase by 20 basis points, what is the approximate change in the market price using the duration approximation?
a
Period | Cash Flow | Discounting factor | PV Cash Flow | Duration Calc |
0 | ($1,000.00) | =(1+YTM/number of coupon payments in the year)^period | =cashflow/discounting factor | =PV cashflow*period |
1 | 80.00 | 1.08 | 74.07 | 74.07 |
2 | 80.00 | 1.17 | 68.59 | 137.17 |
3 | 80.00 | 1.26 | 63.51 | 190.52 |
4 | 80.00 | 1.36 | 58.80 | 235.21 |
5 | 1,080.00 | 1.47 | 735.03 | 3,675.15 |
Total | 4,312.13 |
b
Macaulay duration =(∑ Duration calc)/(bond price*number of coupon per year) |
=4312.13/(1000*1) |
=4.312127 |
Modified duration = Macaulay duration/(1+YTM) |
=4.31/(1+0.08) |
=3.99271 |
Using only modified duration |
Mod.duration prediction = -Mod. Duration*Yield_Change*Bond_Price |
=-3.99*0.002*1000 |
=-7.99 |
%age change in bond price=Mod.duration prediction/bond price |
=-7.99/1000 |
=-0.8% |
New bond price = bond price+Modified duration prediction |
=1000-7.99 |
=992.01 |