I have to disagree with this statement because in most case I think it’s crazy to put 100% in any one investment (even cash), no matter what it is. It is puzzling to me that you can have 100-150 stocks and then but 23% into a single one.
Well, think carefully about what you wrote.
a) those in the US with 100% cash have not done too badly especially in this low inflation environment for a at least 2 decades now. In general, it never happens. Such individuals usually have mortgages that gives them sizable leverage.
b) There are many firms where a 100% investment will not be devastating: BRK, COST, HDB, PEP etc. Each of these firms are actually so diversified effectively that they constitute a proxy to the national or international economy.
c) Jim Mueller (TMFTortoise)- one of the most astute investors and analysts has, I think, > 30% in NFLX and he does not recommend anyone else doing that. I can keep going on this way. And these are all very successful investors with long track records. And I say this despite being the one who has had 250+ stocks in his portfolio for 5+ years now. I rarely sell. Just collect the best in class firms from TMF world.
Anurag