The Double Top or Bottom Chart Pattern is a reversal pattern as its name implies, the pattern is made up of two consecutive peaks or troughs that are roughly equal, with a moderate trough or peak in-between. This reversal could signal an end of an uptrend or downtrend.
Note that a Double Bottom Reversal on a bar or line chart is completely different from Double Bottom Breakdown on a P&F chart. Namely, Double Bottom Breakdowns on P&F charts are bearish patterns that mark a downside support break.
Remember that the double bottom chart pattern is a trend reversal pattern and as such it should be looked for after a downtrend has been established. This is all for the first post in the series of basic chart patterns.