Ascending triangles often lead to dramatic rallies but watch out when they fail. The rising trendline marks a breakdown level as Sigma-Aldrich suddenly rolls over and collapses. The crowd that buys into this pattern provides substantial fuel in the other direction when it fails. Everyone sees the violation at the same time and heads for the exit door in a panic. Note how the selloff quickly cuts through strong support at 32 due to the extreme selling pressure.