I thinks EOS is involved in the drastic drop in the price of the ethereum as EOS collected huge amounts of ethereum around 600K Eth from its token sale rounds which they are dumping gradually as they are the main competitors of the Ethereum blockchain. Also there are some small ICOs are also dumping Ethereum as they have to fund their projects progress and give salary to their teams.
Right, When EOS started to be a competitor, they silently dumping ETH for months causing the price to fall. And then other big ICO follow suit as well hurting Ethereum even more.
Now EOS has already declared war on Ethereum and might be deliberately sabotaging it by dumping more of its stash and liquidate everything in the next coming months.