The Double Bottom Reversal is a bullish chart pattern that indicates a probable upward trend.
The pattern consists of two troughs following each other, with a peak inbetween them that shoudn't be very high but clearly defining the two troughs. It will look like the shape of a W.
If the upward line of the second trough breaks the peak inbetween the two troughs, than that gives you a buy signal.
You should focus on medium and long term timeframes when trading this pattern.
It is preferable that the two bottoms of this pattern are about a month apart.
It is wise to wait to trade this pattern until a key resistance level has been broken through.