GDX is on the verge of breaking below its intermediate trendline.  With momentum already down, a breakdown appears imminent, which would set up a measured move to about $17.00.

Looking at the longer term chart, the angle of descent to the $17.00 level appears to align with past major support/resistance (green horizontal line), as well as the end of the latest fib-cycle (144-day), which originated at the Jan-16 market bottom and has since accurately marked important market turns.