The ones killing it, is the ones that made it sky rocket in the first place. ICO/IPO's peaked the 1st of June, since then the surplus of coins i.e."current mining" has pushed it down a little plus the taking of cash from the bump in price that was created by all these ICO/IPO's as tanked it a bunch.
Just wait another few months when all these ICO/IPO's & investors start to look for some cash, it can get MUCH worse
My personal thought is ETH should have ceased mining at the end of May. Then that in itself would have given a huge huge bump maybe an extra 50% to the price, plus that added to a better plan in dealing with all these ICO/PO's and how ETH is tied to them, I think there would a chance we would be holding well over $500 per ETH
All just my opinion of course!