If you have competence, you know the edge. It wouldnt be a competence if you didnt know where the boundaries lie. Asking whether youve passed the boundary is a question that almost answers itself.
Charlie MungerOur standard prescription for the know-nothing investor with a long-term time horizon is a no-load index fund. I think that works better than relying on your stock broker. The people who are telling you to do something else are all being paid by commissions or fees. The result is that while index fund investing is becoming more and more popular, by and large it's not the individual investors that are doing it. It's the institutions.
Charlie MungerBlack-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.
Charlie MungerIf the technology hadn't changed, they [newspapers] would still be great businesses. Network TV [in its heyday], anyone could run and do well. If Tom Murphy as running it, you'd do very well, but even your idiot nephew could do well. Fortunately, carbide cutting tools [such as those made by Iscar] don't have these types of substitutes.
Charlie MungerIn investment management today, everybody wants not only to win, but to have a yearly outcome path that never diverges very much from a standard path except on the upside. Well, that is a very artificial, crazy construct. That's the equivalent in investment management to the custom of binding the feet of Chinese women
Charlie Munger