Double bottom chart pattern double bottom pattern is a classic technical analysis charting formation that represents a major change in trend and a momentum reversal from a prior down move in market trading. It describes the drop of a security or index, a rebound, another drop to the same or similar level as the original drop, and finally another rebound (that may become a new uptrend). The double bottom looks like the letter "W." The twice-touched low is now considered a significant support level. While those two lows hold, the upside has new potential.