A head and shoulders pattern is a chart formation that resembles a baseline with three peaks, the outside two are close in height and the middle is highest. In technical analysis, a head and shoulders pattern describes a specific chart formation that predicts a bullish-to-bearish trend reversal. The head and shoulders pattern is believed to be one of the most reliable trend reversal patterns. It is one of several top patterns that signal, with varying degrees of accuracy, that an upward trend is nearing its end.