Subject 5. Bond Equivalent Yield

Periodic bond yields for both straight and zero-coupon bonds are conventionally computed based on semi-annual periods, as U.S. bonds typically make two coupon payments per year. For example, a zero-coupon bond with a maturity of five years will mature in 10 6-month periods. The periodic yield for that bond, r, is indicated by the equation Price = Maturity value x (1 + r)-10. This yield is an internal rate of return with semi-annual compounding. How do we annualize it?

The convention is to double it and call the result the bond's yield to maturity. This method ignores the effect of compounding semi-annual YTM, and the YTM calculated in this way is called a bond-equivalent yield (BEY).

However, yields of a semi-annual-pay and an annual-pay bond cannot be compared directly without conversion. This conversion can be done in one of the two ways:

  • Convert the bond-equivalent yield of a semi-annual-pay bond to an annual-pay bond.

  • Convert the equivalent annual yield of an annual-pay bond to a bond-equivalent yield.

Example

  • A Eurobond pays coupon annually. It has an annual-pay YTM of 8%.
  • A U.S. corporate bond pays coupon semi-annually. It has a bond equivalent YTM of 7.8%.
  • Which bond is more attractive, if all other factors are equal?

Solution 1

  • Convert the U.S. corporate bond's bond equivalent yield to an annual-pay yield:
  • Annual-pay yield = [1 + 0.078/2]2 - 1 = 7.95% < 8%
  • The Eurobond is more attractive since it offers a higher annual-pay yield.

Solution 2

  • Convert the Eurobond's annual-pay yield to a bond equivalent yield (BEY):
  • BEY = 2 x [(1 + 0.08)0.5 - 1] = 7.85% > 7.8%
  • The Eurobond is more attractive since it offers a higher bond equivalent yield.

User Contributed Comments 10

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achu: BEY is a defn made for convenience by bankers, but using basic principles we can convert it to true annual/periodic yields
meghanchloe: The explanation here is so much easier to understand than the book.
mad123: Could someone explain the conversion from normal YTM to BEY? and is semi-annual BEY= Annual BEY/2?
Is there a logic to the above formula that I cant read through?
Thanks.
nwarrior: To save time you could just use the ICONV Feature on the BAII+, and convert from nominal to effective.
bidisha: nwarrior: can u show how to do the above example on baII
nerhusbae: 2nd - ICONV
NOM = BEY
ANNUAL PAY YIELD = EFF
C/Y = 2 (semi-annual compounds per year)
NBlanco: anyone know if there is a similar feature on the HP12c that nerhusbae is describing?
federer: please all note that @ nerhusbae comment only works to convert semi-annual pay bond to annual pay, doesnt work the other way around.
Safiya921: No explanation of the Money Market Yield here.
931129: Read & Understand on a fresh brain.