Based on what I observed in the current market, Ethereum is the crypto in the market that is down 90% in his All-time High, based on my research this happened because of the ICO under Ethereum blockchain, all of this ICO dump their Ethereum to fund their project, and some of this ICO are Scam projects, let's say 90%, so what will happen to all the Eth they received from Investors? dump! after the dump this guys exit scam, my prediction is we can see a $50 Ethereum this year or maybe $20, but $20 is highly unlikely to happen.
Your scenario is extremely unlikely, imagine that the price of ethereum will fall to $ 150, what would happen the price of bitcoin should fall to $ 5000, and this event will lead to the fact that bitcoin will actively buy and the entire market trend will change to positive.