The head and shoulders pattern forms when a stock's price rises to a peak and then declines back to the base of the prior up-move. Then, the price rises above the previous peak to form the "head" and then declines back to the original base. Finally, the stock price peaks again at about the level of the first peak of the formation before falling back down.
Trading pattern. Long-range direction of a security or commodity futures price, charted by drawing one line connecting the highest prices the security has reached and another line connecting the lowest prices at which the security has traded over the same period. See: Technical analysis.