In fact, there may be many reasons for dumping a coin. I know some groups of traders who merge with each other and buy some kind of certain coin, create the appearance of a sharp demand for a coin because of what its price goes up and it attracts the attention of other traders who also buy this coin. After that, at a certain point in time, when the price of a coin went up by 100%-200%, this group of traders sells all the coins they bought earlier and gets profit, and we see how the coin gets a dump. This is one example.