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.
Warren BuffettI certainly have no desire to sell a good controlled business run by people I like and admire, merely to obtain a fancy price. However, specific conditions may cause the sale of one operating unit at some point.
Warren Buffett