As far as what I can tell they are traders and not scammers, if all cryptocurrencies will go down then those traders will be scammed by the developers of that coin. So far OP just answered directly without any explanation to support his answer which is really not a good way to start a conversation. We should be open to this topic as he is partly right but not all crypcourrencies are a scam as only a few acts like a pump and dump coin which really don't have any use at all. I would wait for OP to update his answer so that he won't get bad replies in his thread.