Excellent article. The difficulty is that even when clients describe themselves as "long term investors" they become (panicked?) "short term investors" at the speed of sound when there is "too much" volatility on the downside. It is my experience of 35 years that MPT and diversification are often-not always-more effective at keeping clients in the market at all vs taking concentrated, long term positions that cause clients to panic. Just one person's opinion. CIMA 1993