Actuarial Notes

Premium

A premium bond is a bond whose price P is above its redemption value C. The excess P - C is the premium.

P > C

P - C = (Fr - Cj)\,a_{\overline{n}|j}

  • F is the face value, r the coupon rate per period, j the yield rate per period and n the number of coupons left. The premium is positive exactly when Fr > Cj, that is, when the modified coupon rate g = Fr/C is above the yield rate: P - C = C(g - j)\,a_{\overline{n}|j}.
  • Unless an exam question says otherwise, the redemption value equals the face value (SOA's FM notation note). With C = F the test reduces to the familiar one: the coupon rate is above the yield rate, and the price is above par. When C \neq F, compare the price with C and the yield with g, not with F and r.
  • The premium P - C is written off gradually through the amortization of premium as the book value falls to C at redemption.
  • The opposite case, a price below the redemption value, is a bond bought at a Discount.

Identifying a Premium Bond A $1{,}000 par bond, redeemable at par, with 7% annual coupons is priced to yield 5%. Is it a discount or premium bond?

Answer Here C = F = 1{,}000, so g equals the 7% coupon rate, which exceeds the 5% yield. The price rises above the redemption value: P > C = \$1{,}000 The bond sells at a premium; the $(P - 1{,}000) premium is amortized against the above-market coupons over the bond's life.

A Premium Bond Priced Below Its Face Value A 10-year bond with face value 1{,}000 and 5% annual coupons will be redeemed for 950. It is bought to yield 5.2% annually. Find the price, and decide whether the bond is bought at a premium or a discount.

Answer The coupon is Fr = 50 and Cj = 950(0.052) = 49.40. The modified coupon rate is g = \frac{Fr}{C} = \frac{50}{950} = 5.263\% > 5.2\% so the bond is bought at a premium:

\begin{align*}
P - C &= (Fr - Cj)\,a_{\overline{10}|5.2\%} \\
&= (50 - 49.40)(7.6473) \\
&= 4.59 \\
P &= 950 + 4.59 \\
&= 954.59
\end{align*}

The price is below the 1{,}000 face value and the 5% coupon rate is below the 5.2% yield, yet the bond is bought at a premium of $4.59: it is redeemed for only 950, so its book value is written down from 954.59 to 950.