GDX call option activity

I had a bid in to buy 20 (2000 shares) of GDX call options for strike of 35 in 2015.
Basically, for $1k, at anytime GDX is worth more than 35.50 in jan 2015, get all profits.
Alternately sell if the option is worth more in the year ahead.


Today, I saw some insane volume with this option.  interpret as you wish.
Over $500K in options in this one level alone exchanged hands.
See below.  Good luck