The total capitalization of crypto currency market is about $500B so you need to be a big whale to control the prices of the crypto currencies.But I don't think people from here are not have that much ability to control the prices.So we have to make the money using the bumps and dumps accordingly.There is another option to control the bump and dump by spreading the positive and negative news all over the world.If you have these kind of ability the you also can the bumps and dumps.