ROI Correction
John and James, you are both right when it comes to an "approximate" return, but your numbers do not reflect a definitive answer.
In order to find out the most accurate ROI on any investment you cannot use the average formula because it is a misleading and inaccurate depiction of the return. It can be used to get an "idea" as to how well things are working out, but is far from the truth.
The only answer that matters is the after-tax rate. Anything else is "fluff" and should be taken with a grain of salt. You have to use the CAGR formula(http://beginnersinvest.about.com/od/investing101/a/aa081504.htm) to determine the real annual growth for stock, funds, real estate, etc. for any period over 1 year. We all know how to calculate the first year return, so there is no need to debate that topic.
John and James, you are both right when it comes to an "approximate" return, but your numbers do not reflect a definitive answer.
In order to find out the most accurate ROI on any investment you cannot use the average formula because it is a misleading and inaccurate depiction of the return. It can be used to get an "idea" as to how well things are working out, but is far from the truth.
The only answer that matters is the after-tax rate. Anything else is "fluff" and should be taken with a grain of salt. You have to use the CAGR formula(http://beginnersinvest.about.com/od/investing101/a/aa081504.htm) to determine the real annual growth for stock, funds, real estate, etc. for any period over 1 year. We all know how to calculate the first year return, so there is no need to debate that topic.