Yes. Using it as sentiment gauge. This ratio is always acting one step quicker in major points than GDXJ/GDX ratio, so I'm getting the feel of how speculators are positioned. Then I combine it with latest COT's and "swing spots" in CME futures/options volume and open interest figures along with sentiment data of the sector and gold's public opinion readings. Rarely trading these vehicles apart from times I have a solid entry and exit levels.