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Post by Deleted on Nov 20, 2015 10:33:41 GMT
I have been puzzled about the FC Annualised return (after fees and bad debts), i.e. AER return rate, for some time.
I have my own very basic Excel sheet where I listed for years: Date of Deposits(+)/Withdrawls (-); Amount Deposits(+)/Withdrawls (-); Year fraction (autocalculated); Total Invested capital (autocalculated); Fraction invested (autocalculated)
One line for each deposit/withdrawl and at the end the sums.
From my understanding of things (and this is how banks do calculate it), the AER is: AER= Net Earnings (data taken from the FC Summary table)/Sum of invested fractions
But my calculation never matches FC display and I can't understand how and why. (difference is variable: - 0.2-0.4% with my calculation).
Given I assume the Net Earnings as a correct data from FC (I know this is a big assumption but it is to simplify things), the AER should NOT differ at all, as all the possible variables (fees, bad debt, recoveries etc) are taken out of the calculus.
Can anyone shed light or pass their excel to help with the AER calculation?
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blender
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Post by blender on Nov 20, 2015 10:44:53 GMT
You know that FC's calculation excludes available funds and cash tied up in bids (as not lent)? Also I think they include accrued interest but am not sure of that - it is contingent and subject to fees.
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Post by GSV3MIaC on Nov 20, 2015 12:18:36 GMT
You also have to take care of the compounding .. none of the numbers FC usually shows you are simple interest, they are compounded. The only way to calculate a proper AER is to iterate .. i.e. from time of deposit to next in/out transaction, apply (from memory..) multiply by (1+rate)^(number of days/365), then add in the in/out, and do it for the next period, etc etc. When you get to the end use the difference between what the calculation says you should have, and what is actually in your account, to adjust 'rate'. Rinse and repeat until 'rate' isn't changing. Your real(ish) annual rate is (1+rate)^365 - 1. (OK, I ignore leap years).
But yeah, the main variance is uninvested (or at least un-earning) cash. FC only looks at what you have invested.
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nick
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Post by nick on Nov 20, 2015 13:45:19 GMT
I wouldn't rely on FC's stated AER - mine has been wrong for months now after their botched attempt to reconcile my account, and even before that they looked very suspect. I currently just track my simple annualised return on a weekly basis, mainly as a control to pick up any material errors that may have affected my account - my account never reconciles and is typically 3-5% out.......
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