This is a reversal signature pattern. It can be either negative (typical head and shoulders), or positive (inverted head and shoulders). A head and shoulders pattern is one of the more common and reliable patterns. It is comprised of a rally which ends a fairly extensive advance. It is followed by a reaction on less volume. This is the left shoulder. The head is comprised of a rally up on high volume exceeding the price of the previous rally. And the head is comprised of a reaction down to the previous bottom on light volume. The right shoulder is comprised of a rally up which fails to exceed the height of the head. It is then followed by a reaction down. If the right shoulder does not reach the height of the left shoulder, this indicates that the fall could be even more severe. This last reaction down should break a horizontal line drawn along the bottoms of the previous lows from the left shoulder and head. This is the point in which the major decline begins. The major difference between a head and shoulder top and bottom is that the bottom should have a large burst of activity on the breakout.