bond to its coupons can then be determined. Yield to maturity The yield to maturity (YTM) is the discount rate which returns the market price of a bond without embedded optionality; it is identical to (required return) in the above equation. YTM is thus the internal rate of return of an investment in the bond made at the observed price. Since YTM can be used to price a bond, bond prices are often quoted in terms of YTM. To achieve a return equal to YTM, i.e. where it is the required return on the bond, the bond owner must: buy the bond at price , hold the bond until maturity, and redeem the bond at par. Coupon rate The coupon rate is simply the coupon payment as a percentage of the face value . Coupon yield is also called nominal yield. Current yield The current yield is simply the coupon payment as a percentage of the (current) bond price . Relationship The concept of current yield is closely related to other bond concepts, including yield to maturity, and coupon yield. The relationship between yield to maturity and the coupon rate is as follows: When a bond sells at a discount, YTM > current yield > coupon yield. When a bond sells at a premium, coupon yield > current yield > YTM. When a bond sells at par, YTM = current yield = coupon yield Price sensitivity The sensitivity of a bond's market price to interest rate (i.e. yield) movements is measured by its duration, and, additionally, by its convexity. Duration is a linear measure of how the price of a bond changes in response to interest rate changes. It is approximately equal to the percentage change in price for a given change in yield, and may be thought of as the elasticity of the bond's price with respect to discount rates. For example, for small interest rate changes, the duration is the approximate percentage by which the value of the bond will fall for a 1% per annum increase in market interest rate. So the market price of a 17-year bond with a duration of 7 would fall about 7% if the market interest rate (or more precisely the corresponding force of interest) increased by 1% per annum. Convexity is a measure of the "curvature" of price changes. It is needed because the price is not a linear function of