The final leg of a 5-0 pattern with reciprocal ab=cd. Keep in mind the pattern is still valid up to 61.8% retracement (projected 50%)
Per Scott Carney "Harmonic Trading Vol 2" "The 5-0 is an incredibly precise pattern that possesses only two numbers – the 50% retracement of the BC leg and the Reciprocal AB=CD Pattern™."