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5.9 Solution to Problem #2

Solution

 

Given: Coupon = 0%
Discount Rate = 8%
Maturity 3 Years
Face Value: $100,000
Compounding Frequency Semi-Annual

 

End of Period Coupon Interest Interest Expense Amortization Debt Balance
0 $79,030
1 0 $3,161 $3,161 $82,190
2 0 $3,289 $3,289 $85,480
3 0 $3,419 $3,419 $88,900
4 0 $3,556 $3,556 $92,460
5 0 $3,699 $3,699 $96,150
6 0 $3,846 $3,846 $100,000
Total $20,970  $20,970 

Here, the solution has been stated in hundreds of thousands.

 

Analytic comment:

The Amortization for a zero-coupon bond can be calculated in two different ways. One involves extrapolating the relevant Present Value factors from our rate tables and multiplying by dollars in order to determine the increasing debt balances. From these numbers, we can subtract the period-by-period absolute differences in the factors, adjusting for dollars. To illustrate, going from period zero to period one: (0.8219 – 0.7903) ($100,000) = $3,160 (with a small rounding error). Remember: for a Zero, amortization adds to the balance.

The other method for calculating the amortization is by multiplying the discount rate and the balance. To illustrate, 0.04) ($79,030) = 3,161.

Both methods yield the same result. That’s cool!

 

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Fixed Income Mathematics Copyright © 2025 by Kenneth Bigel is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.