It is also called a trumpet shape, which mostly appears at the top. It is a bearish pattern and is a deformation of the head and shoulders top. The price rises for a period of time and then falls, and then rises and falls again. The rising high point is higher than the last time. is high, and the low point of the decline is also lower than the last low point. That is to say, after completing the left shoulder and the head, when the right shoulder rebounds, it surpasses the high point of the head and creates a new high. The entire form starts with a narrow fluctuation, and then expands in the upper and lower directions. By connecting the upper and lower high points and low points respectively, a triangle shape reflected in the mirror can be drawn, which is the head and shoulders top of the new high on the right shoulder. This is the diffusion triangle of a hidden smile.

The diffusion triangle is caused by the impulsive emotions of investors. It usually appears in the final stage of a long-term rise. This is a market that is irrational and out of control. Investors are infected by the market's fierce speculation or rumors. . Originally, investors had become more conservative in their operations. After the right shoulder hit a new high, they started to chase the rise again amid calls for an extension wave in the market. But "the sunset is infinitely beautiful, but it's almost dusk." When everyone is optimistic, the market always moves in the opposite direction. Market impulsiveness and disorganized actions cause stock prices to rise and fall abnormally, causing the high point to be higher than the last time when it rises and the low point to be lower than the last time when it falls back. In addition, in ascending triangles and descending triangles, the significant buying or selling points are the last points in the triangle formation process, as well as the intervention points after effective breakthroughs. In some cases, there will be a retracement after breaking through the triangles. , it is also an ideal opportunity to intervene when pulling back the breakthrough line.