Just had a look on HitBTC and seeing the same wall... still new to all this but could that be done by one person to hold the price up while Bitcoin surges up and other alts are taking a drop? Sort of a way to block others from selling? i.e. put enough in there that you know based on trading volume it won't get eaten up until the BTC surge has plateaued? But then what... would they start break it off in smaller chunks to sell just below that or just remove them from the book and trading continues without a big sell off because the panic is over? Like I say completely new to this so just trying to watch and learn how order books get played