Is a proprietary concept. The correction prior to the final wave in an established trend. Most of the time it has a sideways shape, often a triangle, and then price breaks out in the direction of the established trend. The breakout, out of a Terminal Set-Up, fails to travel 100% of the height of the Terminal Set-Up, and the reversal is several degree larger, or a trend change. In Elliott wave terms we are talking about fourth or B waves.