If you buy something because it's undervalued, then you have to think about selling it when it approaches your calculation of its intrinsic value. That's hard. But if you buy a few great companies, then you can sit on your ass. That's a good thing.
Charlie MungerWe regard using [a stock's] volatility as a measure of risk is nuts. Risk to us is 1) the risk of permanent loss of capital, or 2) the risk of inadequate return. Some great businesses have very volatile returns - for example, See's [a candy company owned by Berkshire] usually loses money in two quarters of each year - and some terrible businesses can have steady results.
Charlie Munger