A double-bottom occurs when prices form two distinct lows on a chart at approximately the same price level. Prices fall to a support level, rally and pull back up, then fall to the support level again before increasing. A double-bottom is only complete, however, when prices rise above the high end of the point that formed the second low.
The double-bottom is a reversal pattern of a downward trend in a stock’s price. The formation marks a downtrend in the process of becoming an uptrend.