@journeyman, I am wondering if it is the trader or the stock which they shadow. I certainly notice that if I put a buy order in for some stocks, an order will appear immediately behind mine and if I delete the order, it will disappear too. My take on those is that they are just trying to build depth close to the market price but far enough away to not get executed. There's certainly some sneaky stuff with bots around orders too but I don't take enough notice to work out their system.
