Open your eyes, page-173

Beware looking at depth as a tool as it is easily manipulated. For example A 1000 share trigger lot when executed can be set as a contingent order to immediately cancel or change price on another order pushing it further away from the bid and meaning it may never get filled. All sorts of games get played . Hidden orders in depth can also be contingent orders and are there specfically to suck punters in. Only real trades are ones executed and rest is noise. In the good old days before when the ASX removed broker numbers you used to put up a order with a specific number that would let the other insto buyers to know to give you a call as you were a volume buyer / seller but now that is all done via messaging. These days they still haveto walk the market up and down to execute orders that are away from the last price or to enable a cross but that is a different legitimate reason not market manipulation.

As for comsec metrics- you have to consider who uses a comsec account ( retail ) and you also need to 3 days later look at the split between brokers. As a example if comsec was retail buying and only 10% of market volume then 70% of that volume is stuff all and not something to follow.

Algo trading can be used to do average pricing and to put a large volume order into a market progressively but also to manipulate but the ASX will never admit . The manipulation is not the orders at market but those a couple of steps away or miles away which some consider relevant even though they may never be executed. If the average volatility of a share is 10% then only orders within that % are likely to be executed is one theory. Add in short trading, CFD's and other leveraged trading / borrowing with brokers changing limits and it all adds colour to what is really going on. It is not as simple as it is often made out.