Subject: Re: Building portfolio models
I admit I do it in a much more primitive way.

To get my overall progress I take the current liquid investments balance (the main account reports in USD). I convert that to Euros and take the simple average of the two, what I think of as "mid Atlantic currency units" (MACU). Most big global currency moves are in one or the other, usually the USD, so a simple average gives you a not-bad idea of true progress of wealth / purchasing power over time.

For more precision:
I have all my current investment positions on a quote page in the IB trader workstation.
(For positions held at other brokerages, I still create a data line at that IB page, also a line for every forex rate of interest)
I export that data page using the "File | Import/Export | Export Page in Legacy Excel Format" as a temp .csv file to get all current quotes and current FX rates.
I open that and paste it into the Excel sheet where I have all my investment positions past and present at one per line, with a column for entry price.
Lookups into the pasted data give me the current prices and current FX for each, so the P/L for each is evident.
I copy the PL column at the end of each month, and freeze the values for the prior month, so I have a single big sheet with the PL (in one currency) of all positions at all month ends.

As mentioned, very primitive. But I can answer any question that interests me: how have I done overall over time, how has each position done, what did any position or the total look like since month X. It has resilience: I have the Excel sheet on my PC so I don't have to worry about the tracking being at the mercy of Google changing things.

The principal disadvantage is that it works so well, and has done so for so long, that I am running into the number of columns (months) that my ancient version of Excel supports. I've had to delete old columns so the older data is now quarterly instead of monthly.

Jim