this is funny.
I also had interest in this kind of groups few months ago, I got profits only with small groups, but I got losses in groups of more than 1000 members because of the basic thing they know the coin before anyone!

The only way I got real profits from them without being involve is always, always setting orders for a real cheap price or sell orders for high prices in the coins where I have positions or Im following to be in.

It happened 3 times, and the last one was yesterday´s night. I was amazed because I just watch in in real time happening in front of me.
I placed an order in NEO for 20 units at 0.0105, price was about 0.0132, but I always place this kind of "buy orders" when Im going to be out of the cryptoworld. I left my notebook with binance app on and two hours later I watched how a BIGGGGGGG list of sellers dropped the price to 0.01, and then seconds later it was back to 0.0128. Of course my order was placed, and I got 20 neos at 0.0105 and I won 0.046 btc in a few seconds.

Also, last week It happened but as seller. I had 80 NEBLs, and since I was leaving the pc to go to sleep I placed a sell order for the whole balance at 0.0048 (price was half of that when I leave the pc). When I wake up and checked binance, I noticed this sale was made in a pnd peak, and you know what? I ordered exactly 162 NEBLs again with the same balance as soon as I noticed that.

So, never try to be in a pnd group because you will lose money, but if you have active positions in any exchange, my tip is you can place a big sell order for double of price if you are going to be out of your pc, because after the pump, the dump drops the price even cheaper.