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 BuffettMany stock options in the corporate world have worked in exactly that fashion: they have gained in value simply because management retained earnings, not because it did well with the capital in its hands.
Warren Buffett