Hi there!

First of all does it depend on demand, buy and sell orders.
If there is no demand there will be no buying, just selling off so price will collapse, also this apply visa versa.

Also the news about a project is very important, there can be a lot of fud spreading around on social media wich can cause alot of fluctuations off price.

The thing is, crypto aint regulated so the price can vary almost every second. Just do your research, check out a project and there roadmap etc, if you think it will last hodl, if you think your projects isnt getting of the ground, sell never hodl! When price movement up stagnates, you sell as quick as possible.

Greetings!