Chapter 4 Valuing Bonds 115
Now suppose you own the 10% bond. A year later, interest rates increase to 12%. Now a new
4-2c Semi-Annual Compounding
In bond calculations, note that price (PV) must be negative while coupon payment (PMT)
and face value (FV) are positive. Mathematically, the inputs in a calculator would still give you the
same answer if you inputted a positive number for price and negative numbers for face value
4-2d Bond Prices and Interest Rates
Bonds may be premium or discount bonds at various times after the bond is issued.
However, as the bond approaches maturity, it will once again converge toward the par value it had
at issue.
Note that longer-term bonds are more sensitive to changes in the interest rate than are shorter-
term bonds, and that lower-coupon bonds are more sensitive to interest rate changes than are higher
coupon bonds. The former is true because a changed discount rate affects cash flows over a longer
period of time in a longer-term bond. When the coupon rate is lower, a given change in interest
rates represents a larger percentage change in the current coupon rate.
A bond is the sum of the discounted value of the coupon interest payments plus the discounted
principal repayment. Note also that as a bond approaches maturity, the discounted value of the
principal amount becomes a larger and larger proportion of the bond’s value.
Figure 4-2 The Relationship Between Bond Prices and Required Returns for Bonds with
Differing Times to Maturity but the Same 6% Coupon Rate
Interest Rate Risks: (Including Inflation and Issuer Risk)
Price fluctuations will not affect an investor who wishes to hold a bond to maturity. However,
an investor should not simply hold a bond to maturity to avoid loss of principal. Investors should
be looking at alternative investments that could offer higher returns. It could be worthwhile to sell
a bond when it is high priced if it is possible to reinvest at an even higher rate.