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

ethereum is not affected by the price of bitcoin, so now even though the increase in bitcoin is very high if altcoin like eth still has no significant effect, the price is still low. this has become a definite thing between altcoin and bitcoin.
which influences if itcoin investors start to withdraw and shift their investment to ethereum. with the increase in ethereum, I think it can increase the price of other altcoins, because we know ethereum has an influence on the development of other altcoins, even though bitcoin also influences the movements of altcoins. but the view that occurred yesterday was altcoin not following the movements of bitcoin