Double Tops
A previous high may act as a target for a new move to the upside or as a barrier that an uptrend may not be able to penetrate. If this resistance holds and prices turn back, the price reversal may form a double top and makes that price area a more formidable barrier to exceed in the future.
Double Bottoms
A mirror image of the double top is the double bottom: Prices drop to the vicinity of a previous low and bounce back up from this support zone. This reversal at a former low can make this level an even stronger area of support if it is tested several times.
