As Chair of the Board of Directors and a founding member of LCM Avocats Inc., where he served as the firm’s first Managing Partner, Sébastien focuses his practice on litigation, commercial law, securities law and arbitration. The business community relies on his ability to resolve complex issues.

Sébastien frequently represents financial institutions, as well as securities brokers and advisors. He assists them in developing and implementing their compliance policies and represents them before civil courts and regulatory bodies.

In 2018, the Barreau du Québec awarded Sébastien the honorary distinction of Advocatus Emeritus (Ad. E.). Year after year, he has been recognized among the leading practitioners in commercial litigation, including in the rankings of Chambers Canada since 2020, The Best Lawyers in Canada since 2023, the Canadian Legal Lexpert Directory since 2015 and Benchmark Canada since 2013.

Sébastien has chaired the Executive Committee of the Class Actions Section of the Canadian Bar Association, Québec Branch, as well as the Québec Advisory Committee of The Advocates’ Society.

Sébastien is regularly invited to speak at conferences. He has also taught at the Université de Montréal’s Faculty of Law, working with participants in the Pierre-Basile-Mignault Moot Court Competition.

Alongside his many activities in the business community, Sébastien is actively involved in his community and participates in various philanthropic initiatives. He serves on the boards of directors of the Société des soins palliatifs à domicile de Montréal (SSPAD) and its foundation (FSSPAD). He has also served as a director of the International Bureau for Children’s Rights and Avocats sans frontières Québec.

“AI, Privilege and Litigation Strategy: What Follows Heppner and Warner. Two U.S. rulings on generative AI and privilege offer early lessons for Canadian and Québec lawyers”, (co-author) with Dany Guimond-Valcourt, July 13, 2026.

« Recours administratifs en matière de valeurs mobilières au Canada: décisions récentes en matière d’abus de procédure, manquements à l’équité procédurale ou à la justice naturelle » (co-author), in Service de la qualité de la profession, Barreau du Québec, Recent Developments in Securities Litigation, vol. 582, CAIJ, 2025.

« Commentaires sur l’arrêt Salko c. Financière Banque Nationale inc. et al., 2025 QCCA 74 » (co-author), LCM Avocats Inc. Blog, March 13, 2025.

« Infraction pénale à la loi sur les valeurs mobilières : la cour d’appel se penche sur la question de la preuve de la culpabilité morale » (co-author), LCM Avocats Inc. Blog, March 10, 2022.

“Penal offence under the Quebec Securities Act: the Court of Appeal addresses the issue of proof of moral guilt”, (co-author), LCM Attorneys Blog, March 10, 2022.

“Liability of brokerage firms for the fault of their representatives: the Court of Appeal reaffirms the applicable principles”, (co-author), LCM Attorneys Blog, August 18, 2021.

« Les ordonnances de type Norwich et Anton Piller dans un contexte d’enquête interne » (co-author), in Développements récents en enquêtes internes et réglementaires, vol. 502, Barreau du Québec, 2021.

« AMF et mandats de perquisition: la Cour supérieure rappelle les grands principes en matière de protocoles de fouille » (co-author), LCM Attorneys Blog, May 13, 2021.

« Délits d’initiés, pénalités administratives et prescription: la Cour suprême met fin au débat dans le dossier Nstein » (co-author), LCM Attorneys Blog, February 12, 2021.

“Inspections, administrative audits and criminal investigations: the Court of Québec reaffirms constitutional Rights”, (co-author), LCM Attorneys Blog, November 30 2020.

« Manquements à la Loi sur les valeurs mobilières: limites à la défense de diligence raisonnable » (co-author), LCM Attorneys Blog, July 31, 2020.

« Pouvoirs accrus pour l’OCRCVM au Québec » (co-author), LCM Attorneys Blog, July 20, 2018.

« Décision importante en matière d’embauche dans l’industrie des valeurs mobilières » (co-author), LCM Attorneys Blog, July 12, 2018.

« L’affaire Baazov se termine en queue de poisson » (co-author), LCM Attorneys Blog, July 6, 2018.

« Communications entre avocats et experts: le privilège relatif au litige et les devoirs des experts » (co-author), in Revue du Barreau du Québec, Fall 2015, vol. 74, Cowansville, Yvon Blais, 2016, pp. 557-571.

« Le rôle essentiel des “gatekeepers” dans le contexte de l’encadrement des marchés financiers – Modifications législatives récentes » (co-author), Service Barreau du Québec continuing legal education, Développements récents en litige de valeurs mobilières, Vol. 376, Cowansville, Éd. Yvon Blais, 2013, pp. 45-75.

“Professional Negligence: Obligations of Investment Advisers and Clients – Mazzarolo v. BMO Nesbitt Burns Ltée”, (co-author), (2009) Professional Liability and Discipline Litigation, Volume XIII, No. 3, 826.

« Les recours collectifs dans le domaine des valeurs mobilières », Conference on Class Actions, Canadian Bar Association – Quebec Branch, 2007.

« Affaire Rankin: La Commission des valeurs mobilières de l’Ontario est déboutée », Le Journal du Barreau, Vol. 39, No. 3 (March 2007), p. 30.

“Québec Secondary Market Liability Regime, New Securities Class Action Exposure in Québec”,  Nota Bene, Heenan Blaikie, 2007.

« Colloque sur les techniques de plaidoirie », Co-organizer and Co-presenter, 6th Edition, The Advocates’ Society, Québec Division, Montréal, June 4–5, 2026.

“Cryptocurrency and Digital Assets under Securities Law”, Co-presenter and Steering Committee Member, Cambridge Forum on Canadian Securities Litigation 2025, Montréal, December 1–3, 2025.

“Specialized Commercial Court: A Model of Good Behaviour? Quebec Superior Court – Overview of the Rules of Practice of the Commercial Division”, Co-presenter, The Advocates’ Society, Fall Convention 2025, Costa Rica, November 15, 2025.

« Recours administratifs en matière de valeurs mobilières au Canada : décisions récentes en matière d’abus de procédure, manquements à l’équité procédurale ou à la justice naturelle » (co-presenter), Bar of Québec’s Continuing Professional Development Conference on Recent Developments in Securities Litigation, October 23, 2025, Plaza Centre-Ville, Montréal.

« Colloque sur les techniques de plaidoiries » (co-organizer and co-speaker), Third edition of the seminar presented by The Advocates’ Society, Quebec Division, Montreal, June 8 and 9, 2023.

« Colloque sur les techniques de plaidoiries » (co-organizer and co-speaker), Second edition of the seminar presented by The Advocates’ Society, Quebec Division, Montreal, June 9 and 10, 2022.

« L’arrêt Prelco et les clauses de non-responsabilité en droit québécois » guest co-speaker for the Legal Department of Hydro-Québec, Montreal, May 10, 2022.

« Les développements récents en enquêtes internes et règlementaires » (co-speaker), Canadian Bar Association, Quebec Division, November 18, 2021.

« Colloque sur les techniques de plaidoiries » (co-organizer and co-speaker), First edition of the seminar presented by The Advocates’ Society, Quebec Division, Montreal, June 7 and 8, 2021.

“Securities Class action: what to retain from the decisions rendered during the last year?”, (co-speaker), Canadian Bar Association, Montreal, October 1st, 2020.
Moderator, “Amendments to the Ontario Class Proceedings Act: Impacts in Quebec”, Canadian Bar Association, Montreal, February 11, 2020.

“The Class Action Chamber of the Superior Court of Quebec, One Year Later”, (co-speaker), Canadian Bar Association, Montreal, November 28, 2019.

“Effective Management Seminar: Legal Issues affecting Chef Compliance officers and Directors”, Canadian Securities Institute (CSI), Montreal, October 22, 2019.

“IIROC Hearing Committee Conference: A Panel discussion with Enforcement and Respondent Counsel”, Investment Industry Regulatory Organization of Canada, Montreal, October 21, 2019.

“Injunctive Reliefs”, The Advocates’ Society, Montreal, October 18, 2019.

“IIROC Hearing Committee Conference: A Panel discussion with Enforcement and Respondent Counsel”, Investment Industry Regulatory Organization of Canada, Montreal, October 21, 2019.

“Recent Developments in Securities Litigation (2017)”, Barreau du Québec, Montreal, December 1, 2017.

“Recent Development: Enforcement”, Litigation Conference, Investment Industry Regulatory Organization of Canada (IIROC), Montreal, September 8, 2017.

“Class Action Advocacy – The Latest from Québec”, The Advocates’ Society, Toronto, February 14, 2017.

“The continuous Growth of Securities Litigation Conference”, webcast produced by The Knowledge Group, January 2016.

“A practical Guide to Making a Difference: Finding Meaningful International Pro Bono Opportunities”,  American Bar Association, 2015 Fall Meeting, Montreal, October 2015.
Moderator, “Class Actions and Settlement Conferences,” Canadian Bar Association, Montreal, May 28, 2014.

« Gatekeepers: le rôle des protecteurs des marchés – du rêve à la réalité » (co-speaker), Barreau du Québec, Continuing legal education seminar on recent developments in securities litigation, Montreal, November 22, 2013.

Moderator, “The Regulators: Trends and Developments in Enforcement Activities Across Canada”, 11th Annual Advanced Forum on Securities Litigation & Enforcement, The Canadian Institute, Toronto, May 15, 2013.

Co-chair, 11th Annual Advanced Forum on Securities Litigation & Enforcement, The Canadian Institute, Toronto, May 15-16, 2013.

Guest speaker at the 20th seminar for lawyers specializing in securities, Autorité des marchés financiers, Mont-Tremblant, October 2011.

Chair of The Canadian Institute’s Securities Litigation & Enforcement Conference, Toronto, October 2011.

« Le recours collectif », Canadian Association of Paralegals annual conference, Montreal, June 2009.

“New Developments in Secondary Market Liability”, The Canadian Institute’s 8th Annual Advanced Forum on Securities, Litigation and Enforcement, Montreal, April 2009.

“Alternative Conflict Resolution Methods”, Insight Conference on Regulations Governing Stockbrokers and Securities Managers, October 2006.

« Recours administratifs en matière de valeurs mobilières au Canada: décisions récentes en matière d’abus de procédure, manquements à l’équité procédurale ou à la justice naturelle » (Co-speaker), colloquium of the Service de la qualité de la profession of the Barreau du Québec on Recent Developments in Securities Litigation, October 23, 2025, Plaza Centre-Ville, Montréal.

• Bar of Québec – 1998

• LL.B., Université de Montréal, 1997
• Canadian Securities Course, Canadian Securities Institute (CSI)
• International Investment Law, University of London (International Programmes)
• Institute of Corporate Directors (ICD) – Rotman Directors Education Program, 2022

• Barreau du Québec (Advocatus Emeritus) – 2018
• Chambers Canada (General Commercial Litigation and Securities) – since 2020
• The Best Lawyers in Canada – since 2023
• Lexpert Special Edition – since 2022
• Benchmark Canada “Litigation Star” (Litigation – Securities law and Financial Markets) –since 2015
• American College of Trial Lawyers (Fellow) (2026)
• Canadian Legal Lexpert Directory (Securities Litigation) – Repeatedly Recommended since 2013

• Bar of Québec
• Canadian Bar Association
• The Advocates’ Society
• American Bar Association
• Institute of Corporate Directors (ICD)
• Cambridge Forums
• The American College of Trial Lawyers (ACTL)