Right as you say. My reference is the movement of Bitcoin trading on the Ethereum pump. Because of Ethereum, I think there is also a correlation with the movement of Bitcoin.
The whole market is centered around the price of bitcoin so the correlation is not only for ETH but all altcoins, the London hard fork on the other hand could push the price of ETH up and could also affect the price of bitcoin, we expect ETH to hit $4k again this month.