Nothing makes sense! There is no way for me to understand who is dumping in this range over and over. Your input to aid me in vanquishing my ignorance is welcome.
I guess this is caused by the fact that the actual float of Bitcoin is not
as big as you think it is.
Most people that you refer to (miners, long-term holders ...) probably have the majority
of their coins in cold-storage or custodial services. These coins are not really getting traded and therefore
don´t really influence the price action. Many Bitcoin users never actually use their funds.
To sum up, I´d argue that the price action on the exchanges is mainly caused by
professional traders, a steady flow of casual investors entering the market and a
few entities that manipulate the market (shady exchanges, pump and dump groups).