I think it's not possible conclude on optimality without firmly understanding the specific goals. The articles says 'But the aim is usually to diversify risk,

I think it's not possible conclude on optimality without firmly understanding the specific goals. The articles says 'But the aim is usually to diversify risk, not concentrate power, by taking capital from the original family business and putting it into a widely spread portfolio.' It uses the word 'usually' and it's also a blanket that's trying to generalize all these parties, while in a reality that may not be true. Here are 3 constructed but plausible goals one may have: 1) Make 100% sure that you remain wealthy (make almost nothing but never lose anything) 2) 9-in-10 chance to do worse than SP500 index, but 1-in-10 chance to get 'literally take over the world' rich 3) Investing in causes that seem good for the world a la green energy, tesla motors, etc As a counter example, I present cases of lottery winners who go broke. There are multiple documented cases of 10+ million and 100+ million winners who lose the majority of their wealth.