if the sellers are just selling, then that is legit... annoying...

if the sellers are just selling, then that is legit... annoying but legit. If they own the buy side too, that is considered Transactions Involving No Change inBeneficial Ownership. Which is a breach of ASX rules.

Problem is that its not hard to just have too separate accounts, one buying and one selling.

The exchanges (ASX in our case) don't mind the HFT traders as they pay the fees and add "liquidity"... which is crap, but thats for another debate. However its a thin line whether they are legal or not especially with the action we are seeing on ANW i.e. selling automatic parcels and timed intervals, and stacking the sides.

I would, and did, suggest to ASIC that this is manipulative trading in breach of the Transactions Involving No Change inBeneficial Ownership rule, and that is was denying price discovery as genuine sellers and buyers could not out-match the robotic seller given they own both sides of the depth.

I have heard nothing, but they'll likely review the tapes in a few weeks and someone will get a nasty gram from ASIC. All a little too late but i'll see if i can squeeze a name out of them if they call (asic have called me before about similiar stuff, so they do take it seriously).