Descending triangle

One of the three named triangles, defined entirely by its geometry. Two or more highs are joined by a line that slopes down, two or more lows are joined by a line that is approximately horizontal, and the two lines converge toward a point. The description is of a range narrowing from one side only: sellers meeting the market progressively lower while the same level continues to halt the falls.

How many touches are needed before the lines may be drawn is not settled. Two on each line is the most common minimum, three is a stricter convention, and a horizontal line drawn through lows that are merely close rather than equal introduces a judgement that different chartists make differently. The pattern is regarded as complete only when a close occurs beyond one of the lines; until then it is a range with a name attached to it.

The formation is named for its shape and not for what follows it, which is the distinction most commentary blurs. A bias toward a downward break is widely repeated, and studies of the pattern find both directions occurring often enough that the bias is a convention rather than a measured property. The mirror image, with rising lows meeting a flat ceiling, is the ascending triangle.