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 BuffettYou get what I call the natural progression, the three Is. The innovators, the imitators, and the idiots.
Warren Buffett