Bull traps usually form with harmonics. There are actually a few ways we can derive harmonic signals here but to keep things as simple as can be, this looks like an AB=CD pattern.
Where the trap comes in two equal (ish) legs and where the final pop (D leg) is the strongest part of the whole correction.
During this final phase, bears are squeezed out and bulls become cocky, complacent and often leave themselves over exposed.
If the AB=CD pattern succeeds here, something nasty tends to follow.