First of all, not all Altcoin is worth it to hold for a long time because most of them are die at once so many people sell their altcoin immediately. But if Altcoin have potential i dont sell it because i know i can get huge earning from it, like in Ethereum but if not or i saw it has no potential then I'll wait for a while until saw a little movement upward then sell my Altcoin. And since Altcoin is now become know there's some of them are worth it and possible to rise.