A single print column that appears at the top of a market profile structure. The tail is usually made up of at least three or more TPOs. It is formed as a result of buyers drying up and not being present in high enough numbers to continue to move prices higher once they have risen to an area that market participants perceive as an unfair high for the session. As the lack of buyers brings a strong imbalance of selling activity in reaction to the low price levels, prices quickly reverse lower, leaving the single print tail in their wake. It should be noted that these areas usually include the taper of volume in the futures market as volumes at each price level get less and less the closer you get to the top of the tail.