As it seems to me, the more hype around the project, the stronger it will fall after a very strong growth.
In my opinion, it is normally happen because after launching of ICO's more people are buy stocks of token and they holding it because they just want to save it for the future value. More traders are doing that they buy high numbers of token then they sell it immediately or hold it.
Traders thinking is always sell their token or coins in high cost. I agree that most of the traders who incurred or collect tokens were always save it, maybe because after ICO's it was growing up. But most of the time after launching of ICO's it was declined their price. It's because after buying of token or coins of the ICO's it will not circulate to the market because most of the users hold it.