I think personally, if Selling ETH is now a very bad decision, as it will surely increase over time. so I do not think there's a good idea because ETH is still the number one altcoin now and it's hard for other altcoins to replace it because the ETH platform is better and gives more benefit to the cryptocurrency community. so I still believe that ETH will support increased BTC prices. ETH is the future so do not be sorry if you sell ETH that you have.