Following is the weekly chart of GDX since septemeber 2011. Since then, the ETF looks like, it is going down in 5 wave impulse pattern (this 5 wave may be wave C of larger corrective structure). The current down move, since around USD 21, may be the final 5th of 5th or it may be the 3rd of 5th (shown in green). Also an impulse move can keep on extending. But, at the same time, any 5 wave move down may turn out to be the last. Hence, It may be good idea to open some long positions at the completion of any 5 wave down move (time frame daily). If the up move afterwards turns out be corrective, then exit those long positions taken earlier.

Market Vectors Gold Miners(Weekly)24 Jul 2015