This was from his 1998 lecture at the University of Florida, and was brought back to my attention through Jeremy Miller's excellent new book, Warren Buffett's Ground Rules: Words of Wisdom from the Partnership Letters of the World's Greatest Investor:
"If you can identify six wonderful businesses, that is all the diversification you need. And you will make a lot of money. And I can guarantee that going into the seventh one instead of putting more money into your first one is [going to] be a terrible mistake. Very few people have gotten rich on their seventh best idea. So I would say for anyone working with normal capital who really knows the businesses they have gone into, six is plenty, and I [would] probably have half of [it in] what I like best."....................
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