Strong trendline/ horizontal resistance, as well as the development of a bear flag gives a good case for a short here.
Trading plan:
A small short entered at 1.5182 gives the ability to capture the move if price fall from the flag formation prematurely on the next downswing.
Next, a more sizable short is entered around 1.5193-.5195, playing off of both horizontal resistance at 1.520 and the upper channel trendline.
The pattern will not be considered invalid without a break of the outside trendline.
Target 1 is the 1.5150 area
Target 2 is the 1.5120-1.5110 area.