Thanks very much for the info ! I'm noob in trading, so I wonder : how reliable is that analysis ? Do most people that want to sell big volumes put their orders in advance ?
Buy and sell walls are not all that reliable, because traders use them to try and manipulate the psychology of the market.
Sometimes someone who wants to buy a lot more at lower prices will put up a huge sell order and scare everyone, but then when the price goes down they buy, and then they remove the sell.
For example, now even the 800k sell wall is gone (it didnt get bought, the person who put it there removed it). A very small amount of buying would drive the price back up to .125 CNY.
It is possible that what I described above just happened. Someone who wanted more Bitshares put up some huge sells, they got the price to go down 10%, they bought lower and then they removed the sells.
I'm not an expert trader myself either, but I think the most important thing is to make sure you are selling after rises, and buying after drops. Not the other way around! Buy low and sell high. Don't sell low hoping it will go even lower, and then end up buying back higher than you sold.