I see this figure everywhere from advice replies to broker margin-maintainence policy to books on trading as the suggested minimum price stock to trade. What is so special about a stock just because it's trading at $15+ vs. a $6 stock or a $8stock for trading? I'm not actually trying to buck the system. Obviously after seeing it repeated everywhere there must be well formulated reasons for the "rule". My guesses were as simple as "a safe market consensus of value" or perhaps some indepth study was done on the odds of profit vs. loss at this dividing line. Does anyone know some of the reasons? I'm curious.