It's blatantly obvious Eth is and has been wash traded by a single entity on Poloniex for literally months now. Their fee structure is setup where someone pushing that volume would have 0.10% taker fees and 0.0% maker fees, so 0.05% if wash traded.
On a slow Eth day of 20,000 BTC volume, that would be 100 BTC per day in wash trade fees. Does anyone honestly believe the Poloniex Eth manipulators pay that much? Hell no.
Why is Poloniex doing backroom deals with market manipulators to artificially pump coins to defraud investors? It's different if some random guy like Wolong decides to pump a random shit coin, but when the exchange itself is involved in the scheme (like Bittrex has been accused of with Bobsurplus), it's pretty questionable.
Why do you assume that there is
one person doing all the trades on Ether? More likely there are lots of smaller traders, who are trading on margin, which is why you see such a huge volume. Ether's volume on Kraken and other places is pretty big too.
When that Mike Hearn thing happened, lots of bitcoin traders switched to Ether - ETH got lucky in that their coin was being promoted at the same time. If the Hearn thing had happened two years earlier, the rush of money fleeing bitcoin would have gone into Doge.
If you look at the btc/usd charts and the ETH/USD charts, they are negatively correlated. This is being caused by bitcoin traders finding something new and more profitable to trade.