This is usually done in scammy telegram groups that offer investment advice. One thing that people didn't cover here is that sometimes the groups "leaders" announce that this specific coin is going to raise because of this news, so they pump the coins slowly for few cents to make it look legit. People on that group will eat the bait and then the massive pump starts, where the "leaders" start dumping and netting profit while the average Joe is left hoping to get his initial investment back.