"K-Ratio" - Which variation?
Author: Carova
Creation Date: 1/2/2021 10:45 AM
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Carova

#1
(From https://www.investopedia.com/terms/k/kratio.asp)

QUOTE:
The K-ratio takes into account the returns, but also the order of those returns in measuring risk. The calculation involves running a linear regression on the logarithmic cumulative return of a Value-Added Monthly Index (VAMI) curve. The results of the regression are then used in the K-ratio formula. The slope is the return, which should be positive, while the standard error of the slope represents the risk.

In 2003, Kestner introduced a modified version of his original K-ratio, which changed the formula of the calculation to include the number of return data points in the denominator. He introduced a further modification, which added a square root calculation to the numerator, in 2013.


Which version of the K-Ratio is calculated by WL? I am attempting to compare the WL result with another person's calculation and I think we are using two different versions of Lars's formula.

Thanks!
Vince
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Eugene

#2
Apparently it's the 2003 version.
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Carova

#3
Thanks Eugene!

Is WL7 planning to use the most recent version that Lars published?

Vince
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Eugene

#4
You're welcome Vince.

No, the Extended Scorecard in WL7 will use the existing version.
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Carova

#5
I would like to lobby that WL7's K-Ratio calculation match that being used in the rest of the industry to maintain an ability to compare results.

I realize that this is a LONE voice! :)

Vince
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Eugene

#6
If there's a C# version somewhere you're aware of we may leverage it eventually.
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Carova

#7
I will look for one.

Vince
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Carova

#8
It appears that Lars most-recent "adjustment" in 2013 is a relatively simple modification to the original formula

https://papers.ssrn.com/sol3/Delivery.cfm/SSRN_ID2230949_code1745920.pdf?abstractid=2230949&type=2

Vince
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Eugene

#9
Apparently yes, it's a matter of multiplying the K-Ratio (2003) by Math.Sqrt(252)/TimeSeries.Count.
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Carova

#10
I believe that the Math.Sqrt(252) factor is just for a Daily Scale and that other appropriate factors would be required for Weekly and Monthly Scales.

Vince
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