Open Markets have been doing that for ages. pick up whatever...

Open Markets have been doing that for ages. pick up whatever they can on ChiX (queue jumping) then 1 second later it appears on the offer a tick higher.

they rely on the retail brokers algorithms of sweeping ChiX first for volumes, once that runs out they start getting into the ASX bids/offers.

always ask your broker to transact on ASX. transacting on ChiX (and most people don't even know they are) just plays into the algo's hands.