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Chapter 10. Bond Prices and Yields. Straight Bond . Obligates the issuer of the bond to pay the holder of the bond: A fixed sum of money (principal, par value, or face value) at the bond’s maturity Constant, periodic interest payments (coupons) during the life of the bond (Sometimes)
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Chapter 10 Bond Prices and Yields
Straight Bond • Obligates the issuer of the bond to pay the holder of the bond: • A fixed sum of money (principal, par value, or face value) at the bond’s maturity • Constant, periodic interest payments (coupons) during the life of the bond (Sometimes) • Special features may be attached • Convertible bonds • Callable bonds • Putable bonds
Straight Bond Basics • $1,000 face value • Semiannual coupon payments
Straight Bonds • Suppose a straight bond pays a semiannual coupon of $45 and is currently priced at $960. • What is the coupon rate? • What is the current yield?
Straight Bond Prices & Yield to Maturity • Bond Price: • Present value of the bond’s coupon payments • + Present value of the bond’s face value • Yield to maturity (YTM): • The discount rate that equates today’s bond price with the present value of the future cash flows of the bond
Bond Pricing Formula PV of coupons PV of FV Where: C = Annual coupon payment FV = Face value M = Maturity in years YTM = Yield to maturity
Straight Bond PricesCalculator Solution Where: C = Annual coupon payment FV = Face value M = Maturity in years YTM = Yield to maturity N = 2M I/Y = YTM/2 PMT = C/2 FV = 1000 CPT PV
Straight Bond Prices PV of coupons PV of FV For a straight bond with 12 years to maturity, a coupon rate of 6% and a YTM of 8%, what is the current price? Price = $457.41 + $390.12 = $847.53
Calculating a Straight Bond Price Using Excel • Excel function to price straight bonds: =PRICE(“Today”,“Maturity”,Coupon Rate,YTM,100,2,3) • Enter “Today” and “Maturity” in quotes, using mm/dd/yyyy format. • Enter the Coupon Rate and the YTM as a decimal. • The "100" tells Excel to us $100 as the par value. • The "2" tells Excel to use semi-annual coupons. • The "3" tells Excel to use an actual day count with 365 days per year. Note: Excel returns a price per $100 face.
Par, Premium and Discount Bonds Par bonds: Price = par value YTM = coupon rate Premium bonds: Price > par value YTM < coupon rate The longer the term to maturity, the greater the premium over par Discount bonds: Price < par value YTM > coupon rate The longer the term to maturity, the greater the discount from par
Premium Bond Price • 12 years to maturity • 8% coupon rate, paid semiannually • YTM = 6% Price = $457.41 + $390.12 = $1,169.36
Discount Bonds Consider two straight bonds with a coupon rate of 6% and a YTM of 8%. If one bond matures in 6 years and one in 12, what are their current prices?
Premium Bonds Consider two straight bonds with a coupon rate of 8% and a YTM of 6%. If one bond matures in 6 years and one in 12, what are their current prices?
Bond Value ($) vs Years to Maturity Premium CR>YTM 8%>6% YTM= CR M 1,000 CR<YTM 6%<8% Discount 12 6 0
Premium and Discount Bonds • In general, when the coupon rate and YTM are held constant: For premium bonds: the longer the term to maturity, the greater the premium over par value. For discount bonds: the longer the term to maturity, the greater the discount from par value.
Relationships among Yield Measures For premium bonds: coupon rate > current yield > YTM For discount bonds: coupon rate < current yield < YTM For par value bonds: coupon rate = current yield = YTM
A Note on Bond Quotations • If you buy a bond between coupon dates: • You will receive the next coupon payment • You might have to pay taxes on it • You must compensate the seller for any accrued interest.
A Note on Bond Quotations • Clean Price = Flat Price • Bond quoting convention ignores accrued interest. • Clean price = a quoted price net of accrued interest • Dirty Price = Full Price = Invoice Price • The price the buyer actually pays • Includes accrued interest added to the clean price.
Clean vs. Dirty PricesExample • Today is April 1. Suppose you want to buy a bond with a 8% annual coupon payable on January 1 and July 1. • The bond is currently quoted at $1,020 • The Clean price = the quoted price = $1,020 • The Dirty or Invoice price = $1,020 plus (3mo/6mo)*$40 =$1,040
Calculating Yields • Trial and error • Calculator • Spreadsheet
Calculating YieldsTrial & Error A 5% bond with 12 years to maturity is priced at 90% of par ($900). Selling at a discount YTM > 5% Try 6% --- price = $915.32 too high Try 6.5% --- price = $876.34 too low Try 6.25% --- price = $895.56 a little low Actual = 6.1933%
Calculating YieldsCalculator A 5% bond with 12 years to maturity is priced at 90% of par ($900). N = 24 PV = -900 PMT = 25 FV = 1000 CPT I/Y = 3.0966 x 2 = 6.1933%
Calculating YieldsSpreadsheet 5% bond with 12 years to maturity,priced at 90% of par =YIELD(“Now”,”Maturity”,Coupon, Price,100,2,3) “Now” = “06/01/2008” “Maturity” = “06/01/2020” Coupon = .05 Price = 90 (entered as a % of par) 100 redemption value as a % of face value “2” semiannual coupon payments “3” actual day count (365) =YIELD(“06/01/2008”,”06/01/2020”,0.05,90,100,2,3) = 0.06193276
Callable Bonds • Gives the issuer the option to: • Buy back the bond • At a specified call price • Anytime after an initial call protection period. • Most bonds are callable Yield-to-call may be more relevant
Yield to Call Where: C = constant annual coupon CP = Call price of bond T = Time in years to earliest call date YTC = Yield to call
Yield to Call • Suppose a 5% bond, priced at 104% of par with 12 years to maturity is callable in 2 years with a $20 call premium. What is its yield to call? N = 4 # periods to first call date PV = -1040 PMT = 25 FV = 1,020 Face value + call premium CPT I/Y = 1.9368 x 2 = 3.874% Remember: resulting rate = 6 month rate
Interest Rate Risk • Interest Rate Risk = possibility that changes in interest rates will result in losses in the bond’s value • Realized Yield = yield actually earned or “realized” on a bond • Realized yield is almost never exactly equal to the yield to maturity, or promised yield
Malkiel’s Theorems • Bond prices and bond yields move in opposite directions. • For a given change in a bond’s YTM, the longer the term to maturity, the greater the magnitude of the change in the bond’s price. • For a given change in a bond’s YTM, the size of the change in the bond’s price increases at a diminishing rate as the bond’s term ot maturity lengthens.
Malkiel’s Theorems • For a given change in a bond’s YTM, the absolute magnitude of the resulting change in the bond’s price is inversely related to the bond’s coupon rate. • For a given absolute change in a bond’s YTM, the magnitude of the price increase caused by a decrease in yield is greater than the price decrease caused by an increase in yield.
Duration • Duration measure the sensitivity of a bond price to changes in bond yields. • Two bonds with the same duration, but not necessarily the same maturity, will have approximately the same price sensitivity to a (small) change in bond yields.
Macaulay Duration % Bond Price ≈ -Duration x (10.5) A bond has a Macaulay Duration = 10 years, its yield increases from 7% to 7.5%. How much will its price change? Duration = 10 Change in YTM = .075-.070 = .005 YTM/2= .035 %Price ≈ -10 x (.005/1.035) = -4.83%
Modified Duration • Some analysts prefer a variation of Macaulay’s Duration, known as Modified Duration. • The relationship between percentage changes in bond prices and changes in bond yields is approximately:
Modified Duration (10.6) (10.7) %Bond Price ≈ -Modified Duration x YTM A bond has a Macaulay duration of 9.2 years and a YTM of 7%. What is it’s modified duration? Modified duration = 9.2/1.035 = 8.89 years
Modified Duration (10.6) (10.7) %Bond Price ≈ -Modified Duration x YTM A bond has a Modified duration of 7.2 years and a YTM of 7%. If the yield increases to 7.5%, what happens to the price? %Price ≈ -7.2 x .005 = -3.6%
Calculating Macaulay’s Duration • Macaulay’s duration values stated in years • Often called a bond’s effective maturity • For a zero-coupon bond: Duration = maturity • For a coupon bond: Duration = a weighted average of individual maturities of all the bond’s separate cash flows, where the weights are proportionate to the present values of each cash flow.
Calculating Macaulay Duration (10.8) Suppose a par value bond has 12 years to maturity and an 8% coupon. What is its duration?
General Macaulay Duration Formula (10.9) Where: CPR = Constant annual coupon rate M = Bond maturity in years YTM = Yield to maturity assuming semiannual coupons
Calculating Macaulay’s Duration • In general, for a bond paying constant semiannual coupons, the formula for Macaulay’s Duration is: • In the formula, C is the annual coupon rate, M is the bond maturity (in years), and YTM is the yield to maturity, assuming semiannual coupons.
Using the General Macaulay Duration Formula • What is the modified duration for a bond that matures in 15 years, has a coupon rate of 5% and a yield to maturity of 6.5%? • Steps: • Calculate Macaulay duration using 10.9 • Convert to Modified duration using 10.6
Using the General Macaulay Duration Formula Bond matures in 15 years Coupon rate = 5% Yieldto maturity = 6.5% • Calculate Macaulay duration using 10.9
Using the General Macaulay Duration Formula Bond matures in 15 years Coupon rate = 5% Yieldto maturity = 6.5% Macaulay Duration = 10.34 years • Convert to Modified duration using 10.6
Calculating Duration Using Excel • Macaulay Duration -- DURATION function • Modified Duration -- MDURATION function =DURATION(“Today”,“Maturity”,Coupon Rate,YTM,2,3)
Duration Properties: All Else Equal • The longer a bond’s maturity, the longer its duration. • A bond’s duration increases at a decreasing rate as maturity lengthens. • The higher a bond’s coupon, the shorter is its duration. • A higher yield to maturity implies a shorter duration, and a lower yield to maturity implies a longer duration.
Bond Risk Measures based on Duration • Dollar Value of an 01:(10.10) ≈ Modified Duration x Bond Price x 0.0001 = Value of a basis point change • Yield Value of a 32nd:(10.11) ≈ In both cases, the bond price is per $100 face value.