- manipulation,
- incredibly stupid,
- a whale mating call,
- some kind of a test of market resolve, or
- the secret best way of selling 500 bitcoins?
It's probably either manipulation, or incredibly stupid. Perhaps the seller knows something we don't, or perhaps he's a retard.
So, now there is two walls. How does that work?
Could be a trick to push the price up, I suppose.
It beats me. Perhaps someone incredibly clever is playing an incredibly clever trick on the market.
Probably the whale who did it managed to sell a few coins fairly high by playing with his walls or something.