Mr. Adam Davidson reports

ARC MINERAL ROYALTIES NOTES SIGNIFICANT RESOURCE GROWTH AT FLAGSHIP MT HENRY GOLD PROJECT

Arc Mineral Royalties Ltd. has noted Sinclair Gold Ltd.'s announcement dated Sept. 14, 2026, of an updated interim Joint Ore Reserves Committee 2012 mineral resource for the Mount Henry gold project in Western Australia.

The updated interim mineral resource comprises 33.9 million tonnes grading 1.2 grams per tonne gold for 1.3 million ounces in the measured and indicated categories, and 14.0 million tonnes grading 1.2 g/t gold for 500,000 ounces in the inferred category. Total contained gold has approximately doubled from the 900,000 total ounces reported when Sinclair Gold acquired the project in February, 2026.

Arc holds a 1-per-cent net smelter return royalty over the entire project, with an option to acquire an additional 1-per-cent NSR royalty for $10-million (Australian), exercisable for 30 days following Sinclair Gold's announcement of a 2.0-million-ounce JORC mineral resource.

Highlights:

• Only 20,426 metres (41 per cent) of Sinclair Gold's continuing 50,000-metre drill program are included, reflecting a July 31, 2026, data cut-off.
• One point three million ounces, or more than 70 per cent of the resource, are in the higher-confidence JORC measured and indicated categories. All resource growth comes from drilling on the Mount Henry and Selene deposits.
• One point six million ounces (approximately 90 per cent) of the combined Mount Henry and Selene Resource ounces are within 200 metres of surface, highlighting the shallow nature of the resource and its open-pit potential.
• Mount Henry and Selene resources constrained within optimized pit shells using a conservative $3,900 (Australian)-per-ounce gold price ($2,816 (U.S.) per oz), approximately 40 per cent below spot at the time of Sinclair's announcement.
• Five rigs are currently drilling, with assays pending from 25 holes outside of the current resource footprint. Both deposits remain open along strike and at depth.
• Sinclair Gold expects drilling to continue through calendar 2026, with another resource update expected before the end of fiscal 2027. Sinclair Gold is well financed, with $38.2-million (Australian) in cash as of June 30, 2026.

Adam Davidson, chief executive officer of Arc, commented: "Sinclair Gold's continued exploration success at Mount Henry demonstrates the value of holding a royalty over a growing asset. As the resource expands, Arc gains exposure to a potentially larger future production base, without contributing to the cost of the drilling that delivers that growth. This is a key attraction of the royalty model and central to our investment in Mount Henry.

"With only 41 per cent of the planned drilling incorporated in this interim estimate, five rigs operating and assays pending from outside the resource footprint, we look forward to further results as Sinclair Gold continues to explore and advance the project."

Mount Henry gold project -- JORC 2012 mineral resource

Mount Henry is an advanced brownfield gold project approximately 20 kilometres south of Norseman and 220 kilometres south of Kalgoorlie. Its resources lie on granted mining tenure with access to regional infrastructure. Further technical details and assumptions are set out in Sinclair Gold's Sept. 14, 2026, announcement, "Mount Henry resource doubles to 1.8 Moz at 1.2 g/t gold."

The updated Mount Henry and Selene resources are reported at a 0.5 g/t gold cut-off within optimized pit shells using a gold price of $3,900 (Australian) per oz. The estimate incorporates new drilling, updated geological interpretations and revised reporting assumptions. Resources at North Scotia and stockpiles are unchanged; and North Scotia retains a 0.4 g/t cut-off and $2,160 (Australian) per oz pit-shell assumption. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

About Arc Mineral Royalties Ltd.

Arc Mineral is a mining royalty and streaming company focused on establishing a portfolio of high-conviction royalty assets. Through a strategic partnership with Karri Capital Partners, Arc combines an experienced royalty management team with project development expertise to pursue both traditional royalty transactions and differentiated royalty creation opportunities. Arc's foundational asset is a 1-per-cent NSR royalty over the Mount Henry gold project in Western Australia, with an option to acquire an additional 1-per-cent NSR royalty.

Qualified person

The scientific and technical information in this news release has been reviewed and approved by Brian Wolfe, BSc, MAIG, principal consultant geologist, an independent qualified person as defined under National Instrument 43-101 (Standards of Disclosure for Mineral Projects).

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