Generate a composite returns for all the shares that I am working on over a dynamic period from a daily price feed in Power BI

I want to be able to generate a cumulative returns for all the shares that I am working on over a dynamic period in the current visual context from a daily price feed in Power BI.

I used the below formula to generate the cumulative returns over a dynamic period from a daily price feed ( for three companies ) in Power BI.

   ReturnsApple = DIVIDE (
LASTNONBLANKVALUE ( Apple[Date], max([Close])  ),
CALCULATE (
    FIRSTNONBLANKVALUE ( Apple[Date], max([Close]) ),
    OFFSET( -1, ALLSELECTED ( Apple[Date] ), ORDERBY( Apple[Date], ASC ) )
)

) - 1

This gives me the image below

However, I am keen to add an additional column - which I refer to as Composite returns. The returns calculates
((1+ apple[result])* (1+ amazon[result])* (1+ meta[result]))-1
for all the selected periods as below

Note: I have the three stocks in separate tables as below

Thank you!

You'll need all of your ticker data in the same table.

1. First, add a Ticker column for each individual table in PowerQuery.
   

2. Then appending your individual sources as a new combined source.
   

3. Load the data to the model.

4. Create a table with a list of your tickers. Tickers = VALUES( data[ticker] )

5. Create a Calendar table.
   

6. Create your measure:

First we declare a variable for the prior close (prior). This takes the value on the last date with non-blank data (LASTNONBLANKVALUE) prior to the visual's selected period (DATESBETWEEN(...,BLANK(),CALCULATE(FIRSTDATE(...),ALLSELECTED(...)))). This is important if the day immediately prior to the selected period has no data (i.e., markets were not open).

Then we take the last non-blank value on or before the last day in context (like before, important if last day is not a market day) less the prior variable we just calculated (prior) and divide that by the prior value to get cumulative change.

VAR prior =
    CALCULATE (
        LASTNONBLANKVALUE ( 'Calendar'[Date], SUM ( data[Adj Close] ) ),
        DATESBETWEEN (
            'Calendar'[Date],
            BLANK (),
            CALCULATE ( FIRSTDATE ( 'Calendar'[Date] ), ALLSELECTED ( 'Calendar' ) ) - 1
        )
    )
RETURN
    DIVIDE (
        LASTNONBLANKVALUE (
            DATESBETWEEN ( 'Calendar'[Date], BLANK (), LASTDATE ( 'Calendar'[Date] ) ),
            SUM ( data[Adj Close] )
        ) - prior,
        prior
    )