Navigating 'Material Change': Takeaways From The SCC's Decision In Lundin Mining

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On November 28, 2025, the Supreme Court of Canada ("SCC") released its decision in Lundin Mining Corp. v. Markowich, providing important clarification on one of the more nuanced areas of Canadian securities law: the distinction between a "material fact" and a "material change" under the Ontario Securities Act (the "Act").

In an 8-1 decision, the SCC dismissed Lundin Mining Corp.'s ("Lundin") appeal, thereby affirming Markowich's position and confirming that the concept of a "material change" must be interpreted broadly, contextually and in a manner consistent with the investor‑protective purposes of securities legislation, rejecting the narrower, "manager-friendly standard" when it comes to what constitutes a "material change" under the Act.