Nobody who uses stop orders to exit from their trades would say you should ever relax that discipline by cancelling an order or lowering the stop price in order to hang on. But some might change that stop order into a market order when something tells them they should. What could that something be? Any rules, or rules of thumb? The question is especially relevant this time of year, because crashes are common in Jan. and Feb., and at this point in the market cycle, at such dizzy heights.