Pretty much how I use GoogleFinance too, bringing it up on the notebook while having my breakfast to get a quick snapshot of where things are at. Created a couple of "what if" formulas (purely for entertainment purposes, as everything can change in a heartbeat) for looking into the future, given current YTD rate of return calculated from actual values:
Where:
B1="Actual YTD %"
B2="Actual Current Value"
B3="Future Value"
B4="Future Date"
The formulas:
=today()+round(nper((365/datedif(date(year(today()),1,1),today(),"D")*B1)/365,0,B2,-B3),0)
=fv((B1/datedif(date(year(today()),1,1),today(),"d")),date(year(B4),month(B4),day(B4))-today(),0,-B2,0)
Assuming a constant return of YTD %, return the date on which portfolio will reach "Future Value", and the portfolio Future Value on the given "Future Date"
I use the second one to estimate (dream about) what an account earmarked for future use might be worth when it is tapped for distributions.