The Head and Shoulders bottom is a popular pattern with investors. This pattern marks a reversal of a downward trend in a financial instrument's price. 

Volume is absolutely crucial to a Head and Shoulders Bottom. An investor will be looking for increasing volumes at the point of breakout. This increased volume definitively marks the end of the pattern and the reversal of a downward trend in the price of a stock.

A perfect example of the Head and Shoulders Bottom has three sharp low points created by three successive reactions in the price of the financial instrument. It is essential that this pattern form following a major downtrend in the financial instrument's price. 

The first point - the left shoulder - occurs as the price of the financial instrument in a falling market hits a new low and then rises in a minor recovery. The second point - the head happens when prices fall from the high of the left shoulder to an even lower level and then rise again. The third point - the right shoulder - occurs when prices fall again but don't hit the low of the head. Prices then rise again once they have hit the low of the right shoulder. The lows of the shoulders are definitely higher than that of the head and, in a classic formation, are often roughly equal to one another.

The neckline is a key element of this pattern. The neckline is formed by drawing a line connecting the two high price points of the formation. The first high point occurs at the end of the left shoulder and beginning of the downtrend to the head. The second marks the end of the head and the beginning of the downturn to the right shoulder. The neckline usually points down in a Head and Shoulders Bottom, but on rare occasions can slope up.

The pattern is complete when the resistance marked by the neckline is "broken". This occurs when the price of the stock, rising from the low point of the right shoulder moves up through the neckline. Many technical analysts only consider the neckline "broken" if the stock closes above the neckline

The volume sequence should progress beginning with relatively heavy volume as prices descend to form the low point of the left shoulder. Once again, volume spikes as the stock hits a new low to form the point of the head. It is possible that volume at the head may be slightly lower than at the left shoulder. When the right shoulder is forming, however, volume should be markedly lighter as the price of the stock once again moves lower.

It is most important to watch volume at the point where the neckline is broken. For a true reversal, experts agree that heavy volume is essential.