Most rules are the same as for contracting triangles, with these differences:
- Wave C, D, and E each move beyond the end of the preceding same-directional subwave. (The result is that going forward in time, a line connecting the ends of waves B and D diverges from a line connecting the ends of waves A and C.)
- Subwaves B, C, and D each retrace at least 100 percent but no more than 150 percent of the preceding subwave.
Most guidelines are the same as contracting triangle, with these differences:
- Subwaves B. C and D usually retrace 105 to 125 percent of the preceding subwave.
- No subwave has yet been observed to subdivide into a triangle.