what would I do if I wanted to buy huge amount of Bitcoin:
buy few hundred bitcoins, excute a market order sell to push the price a bit down, now sure the ask is still above you, so what you need to do is make your bot sell 0.01 Bitcoin constantly to give the impression that price is low and to trick other bots, low sell orders will start building, keep doing all above until the sell orders meet your expectations and than execute a buy market order.
what would I do if I wanted to sell huge amount of Bitcoin:
I would buy few hundred Bitcoins first to give an impression of price going up, than excute one sell market order and right after it a buy sell order of 0.01 to trick people/bots about the last price and repeat
and this is what was happening the last couple of days both when buying and selling....
go here and watch the last trades on the right, this is what is happening, now we are at the selling phase, before we were at the buying phase.