Hi!!
Always take into account this:
"Market value of a bond = PV of future payments (coupons and principal)
discounted at cost of debt (the yield to maturity)".
And:
"PV of future payments (coupons and principal) discounted at cost of
debt (the yield to maturity) = PV coupons + PV of principal"
You know:
Market value of the bond (selling price), PB ;
bond life (the number of future payments), n ;
YTM;
Face value or principal (the last payment, usually if it is not
indicated in the problem statement it is equal to $1,000), Pr.
PV principal = Face value / (1+YTM)^n
PB = PV coupons + Face value/(1+YTM)^n
Then:
PV coupons = PVc = PB - Face value/(1+YTM)^n
Note that:
PVc = Coupon/YTM * [1 - (1 / (1+YTM)^n)]
Then:
Coupon = (PVc * YTM) / [1 - (1 / (1+YTM)^n)]
Knowing Coupon payments we have that:
Coupon rate = 100 * Coupon / Face value [%]
For example if the selling price is $1086; YTM = 6.8% and the bond
life is 14 years we have (use a face value of $1000):
PV principal = Face value / (1+YTM)^n =
= $1000 / (1.068)^14 =
= $398.11
PVc = PB - Face value / (1+YTM)^n =
= $1086 - $1000 / (1.068)^14 =
= $1086 - $398.11 =
= $687.89
Then:
Coupon = (PVc * YTM) / [1 - (1 / (1+YTM)^n)] =
= (687.89 * 0.068) / [1-(1/1.068)^14] =
= 46.77652 / 0.6019 =
= $77.715
Finally:
Coupon rate = 100 * Coupon / Face value =
= 100 * 77.715 / 1000 =
= 7.7715 %
I hope this halps you. Feel free to request for a clarification if you need it.
Regards,
livioflores-ga |