Law360 Canada ( November 28, 2025, 11:52 AM EST) -- Appeal by appellants from a judgment of the Ontario Court of Appeal which granted the respondent leave to bring a claim for statutory cause of action under the Securities Act (Act) and remitted issues regarding certification of a class proceeding to the Superior Court. The corporate appellant, Lundin, was a company with mining operations in different locations including Chile. The individual appellants were officers and directors of Lundin. The respondent was one of Lundin's shareholders. The Candelaria mine in Chile consisted of an open pit mine and underground mines. Lundin detected pit wall instability in the open pit part of the mine. That instability caused a localized rockslide. Lundin did not immediately disclose the pit wall instability or rockslide to investors. Instead, it publicly disclosed the events about a month later. As a result, the price of Lundin's securities fell on the Toronto Stock Exchange. The respondent brought a motion for leave under s. 138.8(1) of the Act to commence an action for breach of Lundin’s timely disclosure obligations and for certification of a class proceeding. The motion judge denied leave and dismissed the motion for class certification. He accepted that the pit wall instability and rockslide might have been “material facts” but ruled that there was no reasonable possibility that the investor could establish a “material change” in the company’s “business, operations or capital”. The Court of Appeal found that the motion judge misinterpreted the statutory test for a “material change” by adopting restrictive definitions of the terms at issue and erred in his application of the test for leave. The appellants submitted the Court of Appeal interpreted “material change” too broadly and erred in applying the test for leave. The respondent claimed that the Court of Appeal correctly interpreted the statutory term and properly applied the test for leave....