Read about a contrary indicator: http://theshortsideoflong.blogspot.com/
http://theshortsideoflong.blogspot.com/2013/04/daily-notes_18.html
From www.grantspub.com:
But for those who buy this and anything related to precious metals mining:
then this is what it feels like: http://youtu.be/2Nax7YiPDfI