Trends/Reversal patterns

Double bottom

Price falls to a low, rises, falls to about the same low again, and fails to go lower. It looks like the letter W.

Reversal patternsBest on 6M, 1Y, 3YAlso called W bottom

Illustration of the double bottom shape. It is a sketch, not real price data.

What it shows

A double bottom has two lows at about the same price with a bounce between them. A line across the top of the bounce is the neckline.

The pattern is complete only when price closes above the neckline.

How we find it

The same code that draws it on your chart follows these steps, with the same result every time.

Find two swing lows within 3% of each other, at least 15 bars apart.
Find the highest swing high between them and draw the neckline at that price.
Require the bounce to be at least 5% above the lows.
Mark complete when a close rises above the neckline by more than the margin.

Starting values: Low match within 3%; Minimum bounce 5% above lows; Minimum bars between lows 15; Margin 1.0%. These are proposed and will be tuned on real price data before launch.

How to read it

Teal dots are the two lows.
The blue line is the neckline across the bounce.
The gold dot is the first close above the neckline.

Status labels you may see

Label	What it means
Forming	Two lows, neckline not broken.
Testing the neckline	Within 2% below it.
Neckline broken	Close above the neckline.

What cancels it

A close below the lower of the two lows.

What traders check next

Volume on the second low compared with the first.
Whether the break closed or only wicked.
Time between the lows.

Limits

Many double bottoms become triple bottoms or ranges.
Equal lows are a matter of tolerance.
The break can fail.

Try it in forecastviz

Open any ticker and choose Reversal patterns → Double bottom in the left menu.
Switch between 6M, 1Y, 3Y to see how the picture changes.
Compare with Double top and Triple bottom on the same chart.

Open on a ticker

Questions

How is it different from support?

Support is the level. A double bottom is two turns at that level plus a break of the bounce.

Is it the mirror of a double top?

Yes.