the consensus seems to be that due to all the ICOs hosted by ETH, seems like logical reasoning, so it's not that surprising.
people buy into ICOs with ETH > company sells it for fiat
seems logical, and now that the ICO frenzy is over, maybe ETH by itself doesn't justify its pice
not only that, the bounty hunter who exchanged tokens to eth and then sold them all, also affected etherum prices. it looks like etherum sold on a large scale and at the same time.