Sirios Resources

Investor Insight

Sirios Resources is advancing one of Québec’s largest undeveloped gold deposits, combining a multi-million-ounce resource base, strong infrastructure access and deep regional expertise backed by the Osisko development ecosystem, creating a clear pathway toward re-rating and growth.

Overview

Sirios Resources (TSXV:SOI,OTCQB:SIREF) is a Québec-based gold exploration and development company focused on advancing a portfolio of high-potential projects in the Eeyou Istchee James Bay region of Québec. The company’s flagship asset, the Cheechoo gold project, ranks among the largest gold projects in the province by resource size. The project benefits from favourable geology, near-surface mineralization, and proximity to existing infrastructure, including road access, power lines and the nearby Éléonore mine. Sirios is advancing Cheechoo through systematic drilling, resource expansion and technical studies with the objective of progressing the project toward a PEA.

In December 2025, Sirios announced a transformational combination with OVI Mining, creating a district-scale gold platform anchored by Cheechoo and complemented by the Corvet Est and PLEX projects. The transaction brings Sirios into the Osisko development ecosystem, strengthening the company’s leadership team with proven mine-building and capital markets expertise, while retaining Sirios’ long-standing geological knowledge of James Bay.

With over three decades of continuous exploration in the region and strong relationships with local and Indigenous communities, Sirios is well-positioned to unlock value through disciplined project advancement and exploration-driven growth.

Company Highlights

• Flagship Cheechoo gold project hosts approximately 3 million ounces of gold, including 1.3 million ounces indicated and 1.7 million ounces inferred, including additional underground resources
• Located in Eeyou Istchee James Bay, Québec, a Tier-1 mining jurisdiction with strong government and community support
• Low strip ratio (2.9:1) and high gold recoveries (92 percent) support attractive open-pit development potential at Cheechoo
• Strategic combination with OVI Mining brings Osisko-backed leadership, capital markets strength and additional district-scale exploration assets

Key Projects

Cheechoo Gold Project

The 100 percent owned Cheechoo gold project is Sirios’ flagship asset located in Eeyou Istchee James Bay, Québec, near existing infrastructure and operating mines. The project hosts a large, near-surface gold deposit with scalable, open-pit potential and higher-grade underground extensions.

A 2025 mineral resource estimate outlines approximately 3 million ounces of gold, including 1.3 million ounces indicated at 1.12 grams per ton (g/t) gold and 1.7 million ounces inferred at 1.23 g/t gold, which includes 446,000 ounces of underground resources grading 3.09 g/t gold. The deposit exhibits a low strip ratio of 2.9:1 and high metallurgical recoveries of approximately 92 percent, supporting favourable development characteristics.

In addition to the current resource, Cheechoo hosts a significant exploration target ranging from 31 to 40 million tonnes grading between 1.27 and 1.45 g/t gold, highlighting strong potential for further resource growth. Sirios’ ongoing work is focused on expanding the resource base and advancing the project toward a preliminary economic assessment.

Corvet Est Gold Project

Corvet Est is a 6,500-hectare district-scale land package located east of Cheechoo within the same highly prospective James Bay geological corridor. The project comprises a historically drilled gold system that has seen limited modern exploration since 2012. Following consolidation by OVI Mining, Corvet Est now offers Sirios exposure to a large land package with multiple mineralized zones and significant upside potential.

Plex Gold Project

The PLEX project is a 21,000-hectare district-scale land package hosting the Orfée gold zone, characterized by multiple structural corridors and underexplored depth and strike potential. Historical drilling has confirmed gold mineralization, and Sirios plans to advance compilation, target refinement and exploration programs to unlock the project’s discovery potential.

Aquilon Gold Project

The Aquilon project is an optioned gold asset located in James Bay and hosts numerous high-grade gold showings, including some of the highest gold grades historically reported in Québec. Recent drilling has outlined a broad gold-mineralized halo with strong expansion potential. Exploration at Aquilon is currently being advanced in partnership with Sumitomo Metal Mining Canada, providing Sirios with continued exposure to exploration upside while limiting capital commitments.

Management Team (Post-Transaction)

Dominique Doucet. – Executive Chairman

Dominique Doucet is a veteran of Québec’s mineral exploration industry with more than 40 years of experience, including over 30 years in the Eeyou Istchee James Bay region. He founded Sirios Resources and has led the discovery of several significant gold occurrences, including the Cheechoo and Aquilon deposits.

Jean-Félix Lepage – Chief Executive Officer

Jean-Félix Lepage is a mining engineer with over 15 years of experience in mine operations and project development. Prior to joining Sirios, he served as vice-president of Projects at O3 Mining, where he advanced the Marban project, and previously held senior operational roles at Newmont, including at the Éléonore mine.

Sean Roosen – Board Member

Sean Roosen is the founder and executive chairman of Osisko Development and former CEO of Osisko Gold Royalties. He played a central role in the discovery, financing and development of the Canadian Malartic mine and is widely recognized as a leader in the global mining industry.

Laurence Farmer – Board Member

Laurence Farmer is CEO of Electric Elements Mining and General Counsel and vice-president of corporate development at Osisko Development. He brings extensive experience across mining, law and finance, with a strong background in corporate transactions and resource development.