For every program line, regardless of which mechanism plug-in the program line uses, you will have the option of ticking the Inverse earnings box.
For example, suppose a program line has a fixed percentage rate of 5% and a total value across the matching transaction lines of £100,000 and the Inverse earnings box is not ticked.
For this program line, calculating the earnings will involve both of the following, regardless of whether the inverse earnings box is ticked:
- Multiplying the percentage rate (5%) by the transaction value for the program line (£100,000) to derive a program line result for earnings (£5,000).
- Multiplying the percentage rate (5%) by the transaction value for the transaction to derive an earnings result for each of the matching transactions.
Now suppose the Inverse earnings box is ticked. Trading Programs will include an additional step in the earnings calculation that involves multiplying each of the following by -1:
- The program line result for earnings (to give an earnings result of -£5,000).
- The earnings result for each of the matching transactions.
The step of multiplying by -1 is always applied as the final step after the program line and transaction earnings have been calculated. Except for this final step, the earnings calculations for a program line where the Inverse earnings box is ticked are identical to those that would be performed for the same program line if the Inverse earnings box was not ticked.
As the inverse earnings step always involves multiplying the calculated earnings by -1, ticking the Inverse earnings box will:
- Generate negative earnings where a positive result would have been returned for a program line where the inverse earnings box is not ticked.
- Generate positive earnings where a negative result would have been returned for a program line where the inverse earnings box is not ticked.