^ ICO hype specially got ETH a lot higher I remember that one. Everyone bought ETH in order to invest into ICO's and there were few with over a billion dollars invested as well, it was like a joke at the time that new projects got that much money.
Nowadays something similar happened, ETH got higher because there were people who wanted to invest into DeFi projects as well which is why I think it is quite obvious that people actually increased the price of all crypto currencies in the same manner, they got into bitcoin, and eth, and made profit, and turned that profit into ETH and that was it.
The ICO hype took the ETH to new levels during 2016 - 2017 rally as everyone was investing in ETH to get into the market and it was a joke that every project was able to raise millions even with shitty ideas and then the scams followed up and it continued till the market had a big correction and this time around there is the DeFi hype along with the ETH upgrade to POS as well as everyone is trying to purchase 32 ETH to stake and there are even group buys to stake the coins.
When it comes to bitcoin the institutional investment is pouring in and they are taking the market to new levels and with the economic situation not that great globally everyone is hedging on the decentralized currency.