Perhaps the most important is the number of hackers who stole Ethereum from several exchanges and immediately sold it because it was as if investors were worried to invest in crypto currency because without any security guarantees, other factors might be because the statement from Vitalik Buterin announced the resignation of core team Ethereum
News after being spread out really take an impact to the market, that statement worried more investors and giving the whales a playing opportunities to shake more the entire community of ETH supporters, better to keep away for awhile since the price is falling again and there's no trace knowing how deep it can go more.