i agree with you:

most miners of coins sell to cover costs while those "playing" a market will buy low and sell high, which is fine and overall healthy for a market. a market has tendencies and not every rapid rise and drop is a pump and dump. many people use Technical Analysis to place price points and many of these people arrive at the same entrance and exit points which cause rapid spikes and dips as everyone rushes to get as close to these points as possible. maybe.