I see where you are coming from their pomhat however the corporations act which encompasses the ASX and its monitoring of all facets of possible price interference does state that this type of activity ( if proven ) is illegal and the ASX must act upon it as per the link below ... failure to do so would be a possible breach of the ASX license given to them by the minister at the time and would have potential legal repercussions for both the ASX and the companies(s) involved.
