This is something I’ve been trying to figure out for a while now, and it’s really bugging me. My brokerage is Schwab, and they let me see what my performance has been over varying timeframes. I use Portfolio Performance because I transferred brokerages towards the end of last year, so Schwab doesn’t have my full performance history. The problem is that when I compare the twr and irr that the two platforms give me for the same time period they end up being different. I even made a new portfolio on PP that mimicked exactly what the Schwab portfolio has in its system (which is just the history from the time of transfer), and the returns were still different.
Does this mean PP’s calculation is wrong or are the two systems just making different calculations? How am I even supposed to know? It’s not like I can check the math that the progams are doing.
I really want to use PP, but if I have to choose I’d trust the numbers my brokerage is giving me. Any advice or insight would be great.