Gold never drops or rises as much as the GDX.. the reason for...

Gold never drops or rises as much as the GDX.. the reason for this is margins. Gold miners rely on margins to make their dow.

e.g. if miner A has an all in sustaining cost of $1000, that fall from $1760 to $1200 is actually a fall of $760 margin to $200 margin (~76% fall). Given most miners are above $1k AISC and that some value is given to stocks for assets, potential and commodity futures, this mis-alignment is always going to happen.

also if gold went to 2400 (30% rise) the margin of the gold miner would double (100% increase)