This practice is illegal, if someone can see an order before it is placed it is called front running and has nothing to do with speed. if the exchange allows these groups to see the orders being placed before they are transacted it is ILLEGAL and the ASX are complicit in allowing it to happen. One of the first reasons given to close down the old floor trading and go electronic was order priority but now CHI-X can put orders in hours after ASX orders but get transacted before the ASX orders.
