Portfolio diversification, if you are not a trader but an investor, it is advisable to have both Bitcoin and altcoins and stable coins in your portfolio, then you will be ready.
It's best to have both if you have good amount of spare money.
Diversification is very important in order for you to rinse whatever trend is approaching, both bitcoin and alts always find it's own time to move upward. if you have good amount of invested money, you just need to wait which is which that will move favoring your assets
then wait for the rest to move as well.