Weighted portfolio growth

How do people analyse this and using what tools or calculations. What I mean by weighted is because I add NEW money little and often to portfolio I find it trickier to calculated returns in a given quarter/year as effectively as I would like.

Example: Many compare returns to S&P500, so if £100 in S&P500 and leave for a year what is return, lets say 12%

But what about if you buy £10 of stock 10 times in the year some will return 12%, others 5% some even negative depending on the price at time of purchase. So whilst you can see portfolio is up/down X% easily, you cant actually see compare the result properly, or particular holdings etc.

Does that make any sense? I have built my own portfolio tracker in excel using formulas but my maths isn’t up to much to work out how to rig this up.


Makes sense to me. I use google sheets to unitise any cashflows, effectively as if my own investment decisions were made as part of managing my own portfolio, and then compare to a global equity tracker fund.

I use a modified version of this.


Thanks, I am gonna need to take some time to go through this haha, then see if I can use parts to achieve what I mean. But sounds good in principle and will post back if any questions :smiley: