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?
They do. I have answered a similar topic regarding this one and justified the answer using this example:
" Let us take ETH for instance. If you want to buy/sell ETH in BTC Market (ETH/BTC), the price is in terms of BTC (i.e. 1 ETH = 0.1 BTC). So if the value of 0.1 BTC now is $700 then 1 ETH = $700, after a day the value of 0.1 BTC went down to $600 then the value of 1 ETH would be $600 as well (saying that the conversion factor of 1 ETH = 0.1 BTC does not change). "
We often experience this when the price is dropping than when the price is increasing. This may be because there are more transactions when the price is increasing, thus, there's much volatility. On the other hand, when the price is decreasing, there are less transactions and the price of altcoins solely depends on Bitcoin's.