Australian Stock Exchange Ltd v McLachlan

The Australian Securities Exchange Limited (ASX) appealed a decision of the primary judge concerning the interpretation of its Business Rules. The dispute arose from the ASX's attempt to charge Mr McLachlan, an individual, with breaches of the ASX Business Rules. The ASX contended that Mr McLachlan was an "Affiliate" of the ASX and therefore subject to its Rules. Mr McLachlan argued that he was not an Affiliate and that, in any event, the relevant Rule, Rule 13.5.1(4), did not permit the ASX to charge an individual with breaches. The appeal was heard by Mason P, Heydon and Hodgson JJA in the Court of Appeal of New South Wales.

The central legal issue before the Court of Appeal was the proper construction of Rule 13.5.1(4) of the ASX Business Rules. Specifically, the Court had to determine whether the word "or" in the phrase "an Affiliate or Participating Organisation" should be interpreted conjunctively or disjunctively. This interpretation was crucial to determining whether the ASX had the power to charge an individual, such as Mr McLachlan, with breaches of the Rules, or if the Rule only applied to entities that were either Affiliates or Participating Organisations, but not both simultaneously. The Court also considered the purpose of Rule 13.5.1(4) to ascertain whether it was intended to be punitive or protective in nature.

The Court of Appeal held that the word "or" in Rule 13.5.1(4) should be interpreted disjunctively, meaning that the ASX could charge an entity that was an Affiliate, or an entity that was a Participating Organisation, or an entity that was both. The Court reasoned that this interpretation was consistent with the purpose of the Rule, which was protective in nature, aiming to ensure the integrity of the market by holding those connected to it accountable. The Court found that the primary judge had erred in his construction of the Rule. The Court of Appeal allowed the appeal and set aside the orders of the primary judge.