If you post and update PortfolioCenter daily, why do the values in your PortfolioCenter database differ from your broker’s online system? Because there is always a processing delay.
Even if you download and update PortfolioCenter daily, your PortfolioCenter database will never be as up to date as your broker’s online system.
Assume you place a trade on Monday. Depending on the time of day you placed it, that trade frequently gets processed on Tuesday — which means you’ll see it in the files you download Wednesday morning — which means the earliest you would see it is in the database is after the Wednesday morning posting. For “trade aways” the settlement time may be longer.
While the lag time has considerably shortened over the years, it has never disappeared. I don’t know of any way around it. Even the fastest computers still require time to process and generate data.
To deal with this processing delay, several managers I work with have a “trading day” — frequently they pick Monday. We can capture Friday’s data over the weekend, so on Monday the PortfolioCenter database is as up to date as possible. If they execute all their trades on Monday and Tuesday, the next Monday’s file is as complete as possible.
When they want to see what happened in their portfolios yesterday or in the last 20 minutes, they log on to their broker’s online system rather than opening PortfolioCenter.
They tell me having a “trading day” offers the extra benefit of improving their workload by consolidating the task of trading into one day. The “trading day” frees them for client meetings, research etc on other days and minimizes the tendency of workload to expand into the time allotted to it.