"The big seller was Gilder Gagnon and although I'm not really familiar with them, I think they acquired this position out of the ashes of Apex Mining when assets were re-organized into Golden Minerals. They have been steady sellers for a few quarters. I should try to find out more."
It would not surprise me Gilder Gagnon made a load of money by buying put options at the start of their selling. I have never seen a stock go down like Golden minerals in 6 months time on no news.