As an exercise, here is the case study for your review with GDX. Tip: The cluster strengths here are much different than with IWM!
First Resistance Cluster: 57.213:58.726 Strength: 26
Second Resistance Cluster: 58.891:59.876 Strength: 9
First Support Cluster: 56.983:55.853 Strength: 5
Second Support Cluster: 55.336:54.076 Strength: 21