[jively]

You can get an accurate "internal rate of return" by calculating it in a spreadsheet like MS Excel. Line up the cash flows and dates in 2 columns. For example,

100000 1/1/2007
10000 1/31/2007
10000 3/31/2007
-150000 8/21/2007

This is 100,000 starting value on 1/1/2007. Then 2 10,000 deposits on 1/31 and 3/31. The current value ($150,000) is negative with todays date.

Then, the function is =XIRR(dollar ranges, date ranges)
example: =xirr(A1:A4,B1:B4)

In this case, the annual return is 44.4%. (The actual return is less, closer to 25% because the year is not over.)

In order for XIRR to work, you have to load an Add-In: Tools | Add-Ins... and choose Analysis Toolpak (or Analysis Toolpak VBA).

-Tom