Fund consultants like to require style boxes such as "long-short," "macro," "international equities." At Berkshire our only style box is "smart."

Risk comes from not knowing what you are doing so wide diversification is only required when investors are ignorant. You only have to do a very few things in your life so long as you don't do too many things wrong.

A pin lies in wait for every bubble. And when the two eventually meet, a new wave of investors learns some very old lessons: First, many in Wall Street (a community in which quality control is not prized) will sell investors anything they will buy. Second, speculation is most dangerous when it looks easiest.

We will reject interesting opportunities rather than over-leverage our balance sheet.

If at first you do succeed, quit trying on investing.

Diversification is protection against ignorance. It makes little sense if you know what you are doing.

It takes 20 years to build a reputation and five minutes to ruin it. If you think about that, you'll do things differently.