Look at market history so I can say it's a cycle. This time all of the money in the market is transfer to BTC, and ETH is just an altcoin, so it's inevitable that cash flow from itself is being transferred to BTC as well, make it can't going up with BTC.
Ethereum is an Altcoin, and of course Altcoins are greatly affected because Bitcoin prices continue to soar,
he is right, because investors switching to Bitcoin causes the Altcoin price to fall, but right now if you look at the Ethereum price is pretty good it can stay above $ 400 when the bitcoin price goes up, compared to altcoins medium and low cap, all down 100%.