There's been quite a lot of news and threads about Polkadot of late and it can only mean this coin has prolly piqued the interest of more crypto users, and that means more demand for the coin and that could be why it's appreciating, it could also mean the devs of this coin are working well on their network, if it's a long term progress, that we'll have to wait and see.
so I'm also keeping some of this coin and hold, maybe I might get lucky keeping it.
If it's not a pump and dump coin, then you could very well be lucky holding it.