WEBVTT

1
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A bond cash value should scale with face amount.

2
00:00:04.183 --> 00:00:07,901
In FinancePy 1.1.2, one public method does not.

3
00:00:08.251 --> 00:00:19,187
For this synthetic bond, face one hundred returns 102.6946. The matching clean-value identity is 101.7264.

4
00:00:19.537 --> 00:00:29,911
At face one million, the difference grows to 9,778.9957. No customer transaction or production loss was tested.

5
00:00:30.261 --> 00:00:31,787
The cause is simple.

6
00:00:31.787 --> 00:00:36,746
Dirty price is scaled by face, while accrued interest stays at face one.

7
00:00:36.746 --> 00:00:39,035
A two-line correction restores the invariant.

8
00:00:39.385 --> 00:00:43,899
All 959 local unit tests and both upstream workflows pass.

9
00:00:43.899 --> 00:00:50,671
The correction is open as FinancePy pull request 256. Evidence at GERO dot U Z.

10
00:00:50.671 --> 00:00:52,477
Look at the mechanism.

11
00:00:52.477 --> 00:00:53,831
Check the evidence.

12
00:00:53.831 --> 00:00:54,734
Then decide.