Both are rising, so both are connected for now.
Let's wait until some correction or sideways, if they will keep tied.
Other coins could be "tied" too, because all are rising
Well and ethereum is next highest in terms of price and but third in the total marketcap. The price is not constant and it always moves according to its Marketing cap on both ends. It seems also there are the same on there increase cap. but eth i observed went down as low as 10% in a week where is btc is only at 1 or 2% when it decreases but goes up in a higher percentage.