Mostly the pump and dump altcoins are happening below the 200 coins in terms of market capitalization wherein the market participants is only few, I do not participate in that kind of pump and dump even there is opportunity because for me the risks are too high because it is manipulating by the whales where one wrong mistake, I can lose all of money. It is easy to make money there but it is easy to lose money there so I still prefer to make investment with altcoins that have potential like XRP and ETH.