some people say they can use some way,such as monitor rsi x or cci x,to detect rise and explosion altcoins 1 or 2 day before.
It's not an accurate information about that. Sometimes their prediction can be true but in another cases there are bunch of failed prediction that already made by them. people were only using technical analyzation to analyze the candle and when it was getting bottomed so hard and people will think if it's already entered the end of the dumping phase.
It’s ok or not?
It's not. You must also need to compare how much good prediction that already made by them all with their bad or failed prediction to get how much accuracy that owned by their prediction. i personally think that the chart or explosion will still remain unknown and it's quite impossible to predict.
Sometimes even when with a good news and the price can't go to the moon. TA has less accuracy compared with FA.