Expanding triangles are extremely rare and they are most common during very large complex corrections. An expanding triangle is formed out of five different waves, and it is characterized by the fact that each wave of an expanding triangle is longer than the previous one. However, there are situations when this does not hold true, as some waves during a running expanding triangle happen to be smaller than the previous one.
An expanding triangle should follow to rules below:
- wave a and wave b will always be the smallest segment of the triangle;
- wave e will almost always be the largest wave;
- such a triangle cannot occur as b waves in zigzags or b, c, or d waves of a larger triangle;
- being the longest wave, the e wave will usually be also the most time consuming wave and it is usually a zig-zag or a part of a complex correction;
- if a trend line is drawn from the end of wave a to the end of wave c, the e wave will most likely break that trend line;
- the thrust of an expanding triangle should be less than the longest wave, in this case wave e;
Like contracting triangles, the expanding ones are coming in an irregular, running, and horizontal variations, with the irregular variation being the most common one. Under this variation, either wave b is smaller than wave a or wave d is smaller than wave c.