Osisko Development Extends Gold Mineralization at Cariboo Gold Project Beyond 700 m Vertical Depth in Previously Untested Areas; Intercepts Include 13.19 g/t Gold Over 3.60 m at 596 m Vertical Depth and 28.90 g/t Gold Over 0.50 m at 718 m Vertical Depth

Osisko Development Corp. (ODV) announced assay results from 11 surface diamond drill holes totaling 8,971 meters at its Cariboo Gold Project in British Columbia. The drilling targeted deep extensions and the untested Shaft-Mosquito Gap area, with approximately 65% of the work conducted outside the current mineral resource footprint.

Key intercepts, measured by core length, include: - IM‑26‑001: 42.42 g/t Au over 1.50 m (111 m vertical depth) - IM‑26‑001: 6.40 g/t Au over 6.30 m (326 m) - IM‑26‑003: 6.17 g/t Au over 7.10 m (517 m) - IM‑26‑003: 13.19 g/t Au over 3.60 m (596 m) - IM‑26‑001: 2.79 g/t Au over 8.25 m (436 m) - CM‑26‑001: 8.81 g/t Au over 2.25 m (370 m) - IM‑26‑003: 28.90 g/t Au over 0.50 m (718 m)

All 11 holes returned composites of at least 1.8 g/t Au, and mineralization was identified in 10 of the holes outside the existing resource boundaries. The company stated that these results reinforce the potential for resource growth at depth, extending beyond the deposit’s average depth of approximately 350 meters.

Osisko Development Corp. (ODV) is an advanced developer, not a grassroots explorer. The Cariboo Gold Project already hosts 2.07 million ounces of reserves and 3.5 million ounces of resources, comprising 1.6 million ounces in Measured and Indicated categories and 1.86 million ounces in Inferred categories. With a market capitalization of approximately $1 billion CAD, the company’s valuation already prices in significant value.

Recent deep step-out intercepts are considered incremental, suggesting potential for depth resources beyond the current average depth of approximately 350 meters. However, these results do not materially change the known mineral inventory or mine plan in the near term.

The stock has faced pressure from financing dilution and a fatal incident. While the drill results may provide a short-term sentiment boost, they lack the gram-metre heft, true-width confirmation, or QA/QC rigor to re-rate the project. The presence of going-concern risk and uncertainty surrounding the remaining Appian facility tranche further dampens the impact of the news.

Osisko Development Corp. is advancing its 100%-owned Cariboo Gold Project in central British Columbia. A 2025 feasibility study outlined a 2.07 million ounce probable reserve averaging 3.62 grams per tonne, with a 10-year mine life. The project is projected to produce approximately 190,000 ounces per year at a level-of-mine all-in sustaining cost of US$1,157 per ounce, yielding an after-tax net present value at a 5% discount rate of $943 million.

The company also operates a small-scale test mine at Tintic in Utah and holds a minority stake in Axo Copper, acquired from the sale of San Antonio. Financing for the company’s activities includes a US$300 million convertible note and a US$450 million Appian project loan, with an initial US$100 million drawn and the remaining tranche subject to conditions. Osisko Development is pre-revenue from mining operations, with ongoing development and exploration funded by cash and new equity and debt.