751 Quotes by Charlie Munger

Opportunity cost is a huge filter in life. If you've got two suitors who are really eager to have you and one is way the hell better than the other, you do not have to spend much time with the other. And that's the way we filter out buying opportunities.

You have to realize the truth of biologist Julian Huxley's idea that 'Life is just one damn relatedness after another' "So you must have the models, and you must see the relatedness and the effects from the relatedness.

Black-Scholes works for short-term options, but if it's a long-term option and you think you know something [about the underlying asset], it's insane to use Black-Scholes.

The idea of excessive diversification is madness.

If you turn on the television, you'll find the mothers of the most obvious criminals that man could ever diagnose, and they all think their sons are innocent. That's simple psychological denial. The reality is too painful to bear, so you just distort it until it's bearable. We all do that to some extent, and it's a common psychological misjudgment that causes terrible problems.

There must be some wisdom in the folk saying: Its the strong swimmers who drown.

In the LBO field there is a buried "covariance" with marketable equities, toward disaster in generally bad business conditions, and competition is now extremely intense.

Black-Scholes is a know-nothing system. If you know nothing about value - only price - then Black-Scholes is a pretty good guess at what a 90-day option might be worth. But the minute you get into longer periods of time, it's crazy to get into Black-Scholes. For example, at Costco we issued stock options with strike prices of $30 and $60, and Black-Scholes valued the $60 ones higher. This is insane.

I have what I call an iron prescription that helps me keep sane when I naturally drift toward preferring one ideology over another and that is: I say that I'm not entitled to have an opinion on this subject unless I can state the arguments against my position better than the people who support it. I think only when I've reached that state am I qualified to speak. This business of not drifting into extreme ideology is a very, very important thing in life