it is true, all altcoin prices depend on the price of bitcoin and ethereum. because bitcoin and ethereum are very widely used altcoins for the exchange of fiat currencies. Moreover, many altcoin or ico currently use bitcoin and ethereum as their coin storage
Erc20 tokens depend on Ethereum and coins depend in general on Bitcoin mostly. Then again ETH in part depend on BTC also.
ERC20 token is depend on the ethereum and ethereum depends on the bitcoin. In fact anything in the crypto is following the bitcoin right now. How the market is become a very volatile when there is a bullish or bearish. It looks like people are gonna be confidence with it.