Reversal patterns, or tops and bottoms, signify a fundamental change in the long term trend. Overview Tops are usually less stable and shorter than bottoms.
Bottoms usually have smaller price variations and are slower to establish.
Volume is usually more important on the upside. The line joining the bottoms of the two shoulders is called the neckline. Due to fluctuations, the neckline is rarely symmetrical or perfectly horizontal. The pattern isn't complete until the neckline is broken. It is often good to wait for confirmation - for example, two successive closes below the neckline.