Hi,
Sheets has a template that can serve in the interim (Google Finance Investment). It starts with a couple of tabs; one is where you can get history of individual stock, another you can enter tickers and share counts and the sheet will track value. Every week or so I check the shares across the accounts and update as needed.
I copied the “Watchlist” tab to separate tabs for each of my accounts then filled in the securities / shares in each of the tabs.
There are some things that aren’t available to lookup (e.g. money market, CD ) so one can override the price column to $1.
I wrote a App Script that each weekday evening captures the current values of each account into a history sheet. I added a pivot then a chart to show value history.
K.