i missed it but it seems to me that it was some whale wars going on yesterday. someone was pushing down the price all day yesterday to bring it down to $7k levels despite a good buy support to keep it above $8k and maybe other whales disagreed with this push down and started trying to prevent it by placing these fake buy walls that were moving and never being filled. in any case they weren't that successful since we are currently at $7.5k!
I have the same impression - whales war, some whales disagreeing on the push down - , especially, while the price was going down quickly I've noticed big buys going on (150-200 BTC in one trade).
And yes, fake walls can be part of such strategy.
However, I was expecting from the other whales already getting the price back to 8k levels...