I'm not a Solana investor, but I think those who have already gained much from this growth especially those who bought SOL in the middle of this year should consider taking profit and enjoy it. Bitcoin is expected to grow more and more bullish as the halving nears and afterwards as its effect is gradually priced in. Also as the approval of Bitcoin spot ETF is about to be handed down by the SEC, this will further push Bitcoin's price up. Altcoins like SOL might be negatively affected.
I doubt that to be honest, the ETF of bitcoin will just gonna make the whole market goes to the direction of growing, the thing with ETF is that, it opens up to much much more investment means the market capitalization of the cryptocurrency is growing.
its unlike some bullish where bitcoin gonna usually raise its dominance and therefore forcing the lesser valuable altcoin to have their market capitalization decreased because all the money moving to bitcoin.
its ETF we are talking about thats gonna be massive that definitely gonna brings up some positive thing not only for bitcoin but also for the whole cryptocurrency as a whole.
I even believe that right now is probably the last right time to invest because once the news about ETF is finally out you will know how much of a price bitcoin gonna reach maybe as high as the previous all time high.
just imagine taking profit at that time would be massive for many people because that just means easy 2-3 times of initial capital for profit.