I have proposed a partial explanation: starting May/20, a few people got wind of something that made them buy all they could. Now those people changed their minds, and dumped everything back. So the price got back to where it was. Is this so much sillier than the narwhals(*) that people have been discussing here?
(*) a large sea mammal reputed to be a cross between a whale and a unicorn.
That's how I see it, too.
If manipulation is: Clever players making money with bullish overexcitement, then it's heavy manipulated. Agreed. Business as usual, on all markets, not only bitcoin.