In the investing world, a two-bagger refers to a stock that gains 100% -- that is, it doubles your initial capital. Doing so in a mere five years is no easy feat. It requires a compound annual growth rate (CAGR) of about 14.9% -- which, incidentally, is pretty much what the S&P 500 has posted in the past half-decade.However, this has been an unusual period; the broader market's average annual return is usually below that level. So returns of this type are by no means a guarantee. But if I had to bet on two ...