Floating exchange rate system may not suit small economies

Currently the main currencies have reasonable exchange rates that there is no arbitrary opportunity; however, there are many currencies around the world, and those different currencies create a complex forex market and increase the possibility of arbitrary opportunities. When people could exploit the arbitrary opportunities, the values of the small currencies will fast depreciate as the securities of these currencies futures could be very volatile  and the cost of avoiding risk is too high. Therefore, if a small economy adopts to the floating exchange rate system, it could make its currency fluctuate violently and create huge shocks to its economy.