Hi,
I have perhaps a tricky issue. In an very interesting article by Darren about how to create a custom index (How to Create an (Accurate) Custom Index; https://www.optuma.com/custom-index) he recommends using a geometric average calculation. A very good idea.
So I have created a custom index of four German stock (SAP - SAP.GR; Linde - LIN.GR; Siemens - SIE.GR and Allianz - ALV.GR) using the custom code editor.
The formula is the following: POWER(POWER=0.25, SAP:GR * LIN:GR * SIE:GR * ALV:GR )
The formula works fine. What the issue for me is to understand the performance of the custom index.
I have crated a Relative Comparison Chart of the four stocks, the DAX, and the custom index (DAXTOPW).
As you can see from the screen shot, all four stocks have outperformed the DAX as well as the custom index by a wide margin (base date 03/06/2009).
Here is my problem: How can it be that the four stocks have outperformed the DAX by a really wide margin AND the custom index of these four stocks has underperformed the DAX?
Is it perhaps not possible to calculate a percent change performance from the geometric index since it already used percentage changes to calculate it?
I have also created a Relative Index Comparison chart to the DAX. This chart also shows a underperformance of the custom index to the DAX.
Any helpful ideas are welcomed.
Thanks,
Thomas