I would just like some clarification on measuring returns on my portfolio. I have invested in approximately 25 shares over a period of two years. The investments I make are irregular and so I believe I have correctly used the XIRR formula in a Google sheet with two columns: one for the date of each purchase and another for the cash value I put into my stocks and shares ISA, NOT the book cost of the investment.
However should I use the total cost of each share purchase to account for the costs incurred when purchasing the share (including stamp duty and broker fees)? For instance, if I transfer £1500 as cash into my stocks and shares ISA but the total cost of the investment is £1490 because of stamp duty and broker fees. Which number should I use: £1500 or £1490.
Lastly, am I correct in not including rows for dividends that I receive from each stock because that is not money I have invested from my own pocket, rather it is a part of my return which is being measured by XIRR?
Thanks for any help in advance; I just want to make sure I am measuring my portfolio returns accurately as possible as early as possible.