30 years for most people is a lifetime. This chart, unfortunately I could not get a better copy as I do not know the source, runs from 1900 to 2014 and shows for every year along the x-axis what one would have earned for an investment held the previous 30 years. So for today, 2014, the chart shows a return of about 400% which is what you would have earned if you started investing 30 years earlier, that is in 1984. I have added time lines vertically and they occur with a certain periodicity of roughly 25 years. Presently we are at an extreme high once again and at the end of such a period. History may not always repeat itself but it sure does rhyme very often. Maybe the market is a wee bit overvalued.