Double bottom
A double bottom is formed by two similar lows separated by a bounce. A break above the intermediate peak signals a possible bullish reversal.
It is the mirror image of the double top. After a decline, price finds support, bounces, comes back to test it and holds a second time. The pattern, often called a “W”, is confirmed on a close above the peak between the two lows.
The theoretical target projects the pattern's height above the breakout. A return to the old resistance, now support, can offer an entry with a tighter stop.
A common variant is a second low slightly below the first, followed by a quick recovery: it traps the sellers who were playing the support break.