Head and shoulders, is a reversal of the upward trend peaked shape. Once confirmed this form, declines can be large, which is much higher than other lethal reversal reversal patterns, stock or index will rally into decline. Before determining morphology, aggressive investors should take advantage of the rally will do before departure clearance as soon as possible; after fell below the neckline, would be really sell signal. Cause as follows: the formation of the left shoulder: significantly increased prices gradually rise, then the amount of shrinkage or flat, prices fell slightly. Forming heads: increasing the amount of re or flat prices above the left shoulder height; then the amount of shrinkage or flat, the stock dropped back. Forming the right shoulder: and then increasing the amount or flat, the stock rose back to about the height of the left shoulder; then after the amount of shrinkage or flat, the stock dropped back; and, after the price plunge neckline broken broken, or when the plunge with immeasurable amount is possible .