As I would see it the cost of Ethereum, as well as the various cryptocurrancy coins either specifically or in a roundabout way depend on Bitcoin. Since Bitcoin is the lord of cryptocurrancy, where it is the principal coin to show up on cryptocurrancy. In cryptocurrancy, Bitcoin has extraordinary specialist in creating other altcoin trips.
Bitcoin affects the value of Altcoin because Bitcoin is the parent of Altcoin, but that doesn't always apply especially for new coins, I often see the movement of new coins outside the Bitcoin path, but indeed if for coins not far from Bitcoin it is more dominant in the Bitcoin movement.