How strongly Altcoin value relate to bitcoin price. Can we know the condition of ETH/BTC ratio by analyzing BTC/USD value ?
There are several factors that influence the price link between bitcoin and altcoin. But not necessarily when bitcoin rises then altcoin rises, or vice versa. Currency exchange cryptocurrency does not stand alone. Each exchange offers several cryptocurrency currencies. There is a pair with, dollars, BTC, ETH or other. When one currency rises, one will trade or find the difference from the currency either with fiat money or other crypto money. Example when btc rises, then people will look for another coin to pairkan with btc, so the coin is pushed the price.