The signals that are provided on these groups are for the benefit of group admins and some other insider people who decide which coin to pump, it's just a pump and dump scheme on most of the groups. They buy the coin first in small amounts and accumulate the coins over many days, once they have reached the threshold then they push the signal of that coin to buy and once the price goes up when people buy the coin then they dump their bags on the late comers and earn profits.
which in essence is a manipulative practice carried out by several groups that are already organized. I've seen a lot of pump and dump groups and the effects are visible and the disadvantages of this practice are also numerous.
It is better to stay away from such groups, trading manually using technical and fundamental knowledge is better and more useful.
There are still people who do love to play with fire on which they do know the risk because it is really involving being manipulative which if you do get in too late then it would really be a total lost of money
but there are ones who do really love to play with risk because you could actually make profits if you done it right but newbies aren't really that suggested to play with this one.
Better to trade on your own and with this you could able to trade on your own and learn from it.