Osisko Metals (OM) investor relations material

Resource scale and geology

• Current global resource totals ~2.1bn tonnes at ~0.3% copper; resource work is expected to finish by year-end, with an update in November and final resource in March.

• Target system scale is 3.5–4bn tonnes, including a potential ~3bn-tonne main pit and 500m–1bn tonnes at DPEX.

• Shallow starter-pit mineralization could add 500m–1bn tonnes, with grade potentially near 0.4% copper and zero strip; strip ratio is expected to decline from 1.5:1 to 1:1.

• Historic drilling focused on higher-grade zones; much of the disseminated mineralization was not assayed, and current drilling and re-assaying are defining the bulk-tonnage resource.

Development plan and economics

• Roads, an all-year deep-sea port and a power corridor are already in place; existing infrastructure is estimated to save more than CAD 2bn, with Quebec power at 5.5 cents/kWh versus 8 cents in B.C.

• Current throughput assumptions are ~160,000 tonnes/day; modeling for the PEA may settle above 200,000 tonnes/day, with potential annual copper production above 200,000 tonnes.

• Current estimated CapEx is CAD 5bn; ideal-case permitting completion is late 2029, followed by a couple of years of construction and concentrate production by end-2031 or early 2032.

• Low-case output is estimated at 500,000 tonnes of concentrate/year at 26% copper, with Glencore retaining offtake; initial calculations indicate ~CAD 1bn annual free cash flow at CAD 4–4.50 copper.

• At CAD 5–7 copper, estimated free cash flow would be more than double Canadian Malartic's when it began operating in 2011.

Local considerations

• Consultation is ongoing in Murdochville; depending on the final pit shell and operation scale, up to 400 homes may be affected, with some potentially requiring relocation.