I think you can sell ethereum to buy solana and it might be long term or short term whatever, that is profitable strategy i think.
Btc is future gem in strong hand, i don't think you should to sell btc to buy instead of solana or any token.
solona is still very new. sometimes people feel hesitant to enter solona. that's because the hype is very strong, especially for a project that sells with the solona network. they soon found a good market.
if have more ETH I guess it's ok to share it with solona to keep up with the market hype. quite an attractive strategy for short profits. because solona is still a lot of development.