Various bond features largely affect the degree of correlation between the bond's prices and the bond's interest rates. Some of the bond features that affect bond's interest rate risk are - maturity, coupon rate and embedded options.
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Maturity Period: The degree of bond price sensitivity to its interest rate changes depends upon its maturity period. Longer the maturity period of the bond, greater would be the price sensitivity to change in the interest rate of the bond, assuming that all other factors to be constant.
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Coupon Rate: Assuming that all other factors are constant, the degree of bond price sensitivity to its interest rate changes depends upon its coupon rate. Higher the coupon rate, lower is the degree of sensitivity to changes in interest rates and vice versa. Further, zero coupon bonds tend to have higher price sensitivity to interest rate changes compared to the bonds having a coupon rate.
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Embedded Options: The value of the bond with embedded option will depend on how the value of the embedded option changes with the interest rates. For example, let us consider a callable bond. We know that when interest rates decrease, the price of an option-free bond increases. However, in a callable bond, an increase in price is not as much as it is in an option-free bond. Let us try to understand this by separating the price of a callable bond into two parts.
Price of callable bond = Price of option-free bond - Price of embedded call option
The price of embedded call option is deducted because it is of value to issuer; but for an investor it is a disadvantage. Therefore, the price of a callable bond is less when compared to the price of an option-free bond. Now, when interest rates decrease, the call option value increases because it becomes more valuable to the issuer; and when interest rate decreases, both the price of option-free bond and the price of call option increase. This results in a relatively lesser change in the price of a callable bond when compared to the change in the price of option-free bond.