Do they really? I often encounter this statement. And i have no idea as to why. This past few days, bitcoin is on the rise and most certainly than not altcoin's price surely follows. I am not saying this is bad but altcoins have very little in common with bitcoin. And they are certainly not carbon copies of bitcoin either. Why the heck is their price so closely connected despite being so fundamentally different?
Yes, they follow the flow of bitcoin even in the market. I think because of coin are pair with the bitcoin so they depends in bitcoin price.
Not every time as there could still be some exceptions somehow. At least, we have seen a lot of altcoins resisting such movements in the case where bitcoin is not bringing a favorable condition for them. For instance, doge really gave a huge push recently, despite the market tending to move down hugely but still tried to test the previous high few months back. Generally though, we all know that altcoins are just some sort of distraction from the real deal and as long as they will keep being there, they will certainly be tied to the movement of bitcoin.