If you get reamed don't say you weren't warned. In 2008 there were repeated instances where the futures gapped ~20 handles overnight, clearing out the stack and gapping over your stop, filling you on the other side for hideous losses. Stop orders are worthless when this happens -- all they do is lock in a loss as you fill on the other side (which usually is the extreme print) and then the market reverses some of the move, costing you twice.