Many of the telegram groups which give signals are run by the same people, I have noticed on multiple occasions of the groups giving the same signals. Many of the groups also conduct coordinated pump and dumps, and they usually send it in all the groups to gather a greater audience. Although some of the signals turn out to be correct, always do your own research before making a trade.
Know one knows the Crypto market too professionally to be able to give consistently signals that will always come out accurately. It is a dice. Some signals make profit those who heed to it some may loss. The most important thing is to always do your own research. Let their signals point you to the coin and you make your study weather to invest or not.