即使是芒格在阿裏巴巴的投資也不算成功，3個股票就足夠分散的觀點有點過了。

You may not know what you don't know，要對潛在的黑天鵝有敬畏之心。反方的觀點是：diversification is only the free lunch in investment https://books.forbes.com/author-articles/diversification-is-the-only-free-lunch/