The slight decrease may be due to manipulators, but the decrease Bitcoin has been experiencing is really deep. Bitcoin is struggling to keep the price around $6000. In my opinion, the decrease is caused by both manipulators and real selling.
I think it's mostly fear. People don't want to sell but they are afraid of losing value and each time Bitcoin closes to the point where they bought thay sell to save themselves. The only thing that is holding Bitcoin above 6000 is the ETF decision. People are greedy and fearful at the same time and now greed is fired up y that small spark of ETF and the rest is fear.