Ethereum is the best partner of bitcoin, during 2017 ethereum prices were around 5% of the price of bitcoin. when the bitcoin price is $ 5600 then the ethereum price is $ 280
But why since 2018 until now when bitcoin has reached $ 11 707, ethereum is still $ 227. The ethereum price should be $ 585.
What happened

if bitcoin price is $ 20 000 then ethereum price is only $ 600

if you want to know why the current Ethereum price is difficult for to go up because the bullsrun only happens to Bitcoin and Altcoin doesn't following with the increase of Bitcoin prices anymore. this situation is certainly very different from last year, but some scientists crypto believe if there will be a big pump at the price on Ethereum at the end or the coming year.
yes it is true that bictoin currently dominates in the crypto market, but I am still sure that there will be time for ethereum and other altcoins to pump on the market. I think the current market situation is a correction, because altcoin in 2017 has been pumped to the highest price, and now the market is testing altcoin holders to stay calm and not panic in selling.