The euro-dollar chart shows the consequences of a failed triangle breakout.
The euro-dollar developed an end-of-downtrend pattern starting in March 2015. The pattern was defined by a strong resistance level near $1.14 and the up-sloping trend line B, a combination that created an up-sloping triangle pattern.
The up-sloping triangle pattern is usually associated with an upside breakout. So, as the price activity approached the apex of the triangle, traders were preparing for an upside breakout.