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?
It is because of the trading pairs, when you are looking at the trading tables you can see that all of the altcoins have their trading pairs with bitcoin which means if the volume of bitcoin being traded goes down then the volume of the altcoins that are being traded goes down and that is how they follow the price of bitcoin, it is really simple