When BTC falls, most altcoins follow it but when it rises altcoins do not with less force. The last year is proof. With the naked eye, we see the devaluation of altcoins!
yes, that's a true fact. The BTC is still now the most dominant coin and certainly its price effects to the market. So when it fails the altcoins follows it. But when it increases then the traders try to sell the altcoin and go back to the basis-BTC. That's why I think that situation happens.