Your portfolio will get to a certain size that, if you do not manage its exposure to volatility, your portfolio might not be able to last long to generate adequate cash flow for your use. I have seen a lot of good investors, and mediocre investors generate an astounding rate of return these past 10 years. The reason they could do that can be a mixture of good investment processes and also favourable luck. What I noticed as well is that their portfolio tends to be concentrated as well. They put in the effort to prospect, watch the stock carefully, focus on following the daily ongoing news flow affecting their small portfolio of stocks. They weed out the non-performing ones and let the well-performing ones run. This is very active management. They are no different from a businessman putting their heart, brain and sweat into it. The reward is a great rate of return....