[BUG] Showing wrong currency value at Holdings

[sertxudev]

Hi, awesome work!

I've noticed account holdings are shown with the account currency (EUR):

These should be:

Total value	Today's price
€9,15 €9,64	€4,58 €4,82

The values shown are retrieved from Yahoo finance, which are stored in USD.

The account holdings should be converted to EUR (or whatever the account currency is).

The other values in the account are working as expected.

So the bug it's only at the account holdings table.

[MarcinFrankowski]

The problem seems to be caused by the calculation logic in the HoldingsService. It's using the holding currency instead of the asset currency to get the exchange rate.

Additionally, there's book_value_converted field that doesn't make much sense to me, since it's not calculated using the exchange rate from day of the activity but the current exchange rate

It gets even more interesting when you have 3 currencies in the setup.

1. Set up currency A as a base currency
2. Add 2 accounts with B and C currencies
3. Add the same BUY activity of any asset to both accounts and compare the numbers on the account and holdings pages

I think the discrepancies come from the confusion around book_value
For examample if we have an account in currency B but the asset currency is C, then the value of market_value is in currency C but book_value is in currency B. What's even more confusing both of values are converted using the same exchange rate to the base account currency A
this code does that

[MarcinFrankowski]

I was able to fix the values on Account Holdings page with some debatable calculation changes, but discovered that the same logic is used for the Holdings Page and the fix can't be applied to display correct value on both pages.
My take is that the root cause is the data model structure. The Holding class has values in different currencies. The currency conversion needs to be improved, and it should take into account the context of where the values are presented. For example it should use the account currency on the Account Holdings page and base currency on the Holdings page.

The Holding page gets more complicated when you have the same asset on two account with different currencies. Right now it will add simply add the book values even if the currency does not match (ie. 100$ + 100€ = 200$)

[rafaelgreca]

Same problem here with VWCE and XEON stocks.