Better to hold strong altcoins now if you still have interest in them, I believe that the altcoins that will perform very well in future are strong altcoins with good useful cases, there is still chances of making big profits from altcoins but not shitcoins anymore
At the moment market is not stable, it is very risky to buy altcoin now. Even though the price went up, it was only a slight reflection, then dropped deeper. No matter how good altcoin is, you should never love it, even altcoin is as good as Matic, the price can drop -50% in a day.