I think, yes of course, all the altcoins prices are dependent on bitcoin. Absolutely all coins immediately react to the change in the rate of BTC. BTC is growing, growing, everything else falls BTC and everyone falls for him.
And yet, as I am watching the Coincap app on my phone I can distinctly see that while BTC price goes down by the second, the prices of some coins can go up. On a daily basis, they can be even inversely correlated with respect to BTC.