There aren't many insiders I think, there's only a few developers, the guys from Nocks and Rijk. What can can happen is that PoW2 and/or SegSig is/are delayed and/or some features not possible. I think it's all panic selling, end of 2017 a lot of new people stepped in and thought they were on their way to get rich fast and now that the price was stable for a while around 0.20 they possibly step out while taking some profit and then the snowball effect kicks in.
I still see a good future for Gulden and now have a new chance to buy low again ;-)
SegSig the death of Gulden for a few months, once they drop SegSig and release PoW2 the price will increase. I do give the devs credit for being bold on SegSig but it was a major setback for the coin and time waster.