Bonds are usually recognized by yields, which change from time to time owing to many market forces. There exists an inverse relationship between the bond price and the interest rates. When the interest rates rise, the bond's price decline; and when interest rates decrease, the bond's price increase. As the price of the bond fluctuates with market interest rates, an investor is exposed to a risk because the price of a bond held in his portfolio will decline if market interest rates rise. This risk is called interest rate risk.