These very long term traders are generally just the big FIIs who have access to information which retail folks don't. These people generally just create groups of their own and manipulate the market to buy at the deeps and accumulate during bear markets. And they know how to pump the markets as well. Moreover the main thing is that they work in an ecosystem of media, social media, bankers etc. And all of them work as per their directions and help them in creating the wind that they want to about the market.
You are pointing to whales. Perhaps, the idea to manipulate the market isn't new to us and we are already aware of the situation that can be possible for these whales since they have the money and the capability to do it. But if you are just normal investors who just hold and wait for the market to rally, you have nothing to do but just to become patient. Too far from how these whales make action but yes, they both buy more potential coins during the dip and sell them at a high price. Their intention is to make profit, yet they make their own way of doing it.