Investors should be skeptical of history-based models. Constructed by a nerdy-sounding priesthood using esoteric terms such as beta, gamma, sigma and the like, these models tend to look impressive. Too often, though, investors forget to examine the assumptions behind the models. Beware of geeks bearing formulas.

Whatever you like to do, make it a hobby and whatever the world likes to do, make it a business.

Take the probability of loss times the amount of possible loss from the probability of gain times the amount of possible gain. That is what we're trying to do. It's imperfect, but that's what it's all about.

I think confidence will come back.

Of one thing be certain: if a CEO is enthused about a particularly foolish acquisition, both his internal staff and his outside advisors will come up with whatever projections are needed to justify his stance. Only in fairy tales are emperors told that they are naked.

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.

I don't need 15 houses. Owning real estate doesn't mean much to me. I don't like to think about things like that. I don't need 12 boats, or even the world's largest boat with a crew of 80. I'd have to take care of them, to worry about them. I get a lot more fun out of life without all the bells and whistles.