Trying to obtain the ROI value for an investment portfolio.

I am having an issue with getting the right sort of formula for an ROI value The value changes as the month progresses. See July totals in yellow for how it is set up to calculate the various cells in the same row.

I tried using sumifs but I’m not sure if there a different and easier way to attempt this, as there are lots of elements to this formula to enable it to work correctly and I am by no means a formula expert. The daily entries will make the ROI value change as the day date increments by one until the end of the month arrives and holds the value. When the next month starts the whole process is repeated for August Sept Nov etc.


I have att: a sample sheet for you perusal

hI JeteMc, Thanks for your input, I have never used sumproduct before and never knew how to activate it either, so thanks for the valuable info. If you take a look at cell J82 make it =100,000 which is the same as L$2. Now when you veiw cell O27 you will notice that the resulting figure to my mind doesn't appear correct. I have formatted the cell O27 as a % but still see the result that looks incorrect. Is it that I cant see the wood for the trees? Ha Ha.

Sorry I have been away for a few days. Thanks for your time and input, it great to get some advice from a proffesional person who understands what is being asked.
Take an early finsh for the day ( ha ha).
Cheers
Del..