Once upon a time I generated a spreadsheet that kept track of your portfolio ... here.
>Hmmm, too complicated. What if I just wanted ...?
Yes, exactly. So here's a basic portfolio tracker which does nothing more than download prices to update your portfolio.
>And it looks like ... what?
Like so:
And there's an explanation which looks like this:
>I can't understand why ...
Just click on the picture to download the spreadsheet ... and play!
 Spreadsheet may not be exactly as shown 
>Why would anybuddy want such an animal?
You can calculate Sharpe Ratios and Volatility for each asset, annualized returns, correlations etc.
You may also want to plot prices or returns for each asset or the distribution of weekly returns or ...
>If you have some facility with Excel, right?
Uh ... yes. But it's great fun and you can change your mind concerning what you want to calculate and you can modify the spreadsheet as you wish and ...
>If you have some facility with Excel.
Yes ... and did I mention: it's FREE!
