I participate in a few trading signal groups on Telegram, I consider them pump/dump groups with tens of thousands members. Each group has its own characteristics: there are groups that specialize in technical analysis, then share with members and charge monthly fee; on the contrary, there are groups that focus on the power of community to pump/dump: they also do technical analysis but intentionally use buying/selling power from tens of thousands people and trading volumes of hundreds of thousands $ to impact token price which they target. In the end, group owners and early investors will profit, while those who are slower will suffer losses.
I believe that trading should be conducted with careful analysis instead of completely trusting other people's signals. I also only refer to the reviews of such signal groups to get suggestions for some potential trading pairs. The analysis process, order entry, stop loss, and profit taking are all conducted independently by myself.