FIRO Surges 12.2% as Osisko Gold Confirms High-Grade Proserpine Discovery

• Osisko Gold Group Inc. confirmed high-grade gold structures at Proserpine, located 7 km from its permitted Cariboo project in British Columbia.
• Initial drilling results expanded the known mineralized footprint to 1 km by 0.5 km, with gold intersected from near surface to depths beyond 400 meters.
• The discovery suggests potential for open-pit bulk mining alongside the planned underground operation at Cariboo, validating the regional greenfield target.
• Osisko resumed drilling with three rigs and plans an additional 26,500 meters to expand the resource base and test the Proserpine Northwest area.
• The stock jumped 12.2% to $3.83, reflecting market enthusiasm for the exceptional grades and the significant exploration upside remaining at the site.

Osisko Gold Group Inc. announced its initial diamond drilling results from the Proserpine regional greenfield target, a discovery that has significantly altered the geological outlook for the company's primary assets in central British Columbia. The program, which completed 6,463 meters across 14 holes between February and May 2026, has confirmed the presence of a significant new gold mineralized system of scale. Located approximately seven kilometers southeast of the Cariboo Gold deposit, Proserpine was identified as a high-priority exploration site due to historical gold-in-soil and rock anomalies covering a broader area of 6.0 km by 1.0 km.

The drilling results have expanded the known mineralized footprint at Proserpine to roughly one kilometer along strike by half a kilometer in width. Gold was encountered from near surface to depths beyond 400 meters, with the mineralization remaining open in all directions. This openness indicates substantial exploration upside, as the current drilling has only tested a small portion of the larger target area. Chris Lodder, President of Osisko Gold, stated that the results highlight the potential for a significant new gold mineralized system of scale located close to the permitted Cariboo project.

What do the drilling results indicate for future mining methods?

The initial drilling results at Proserpine have revealed a combination of high-grade gold structures and broader lower-grade zones that together suggest potential for open-pit mining. Highlight intercepts include 95.93 grams per tonne gold over 4.60 meters at 71 meters vertical depth, which includes a 50-centimeter interval grading 873 grams per tonne gold. Another standout hole cut 5.46 grams per tonne gold over 8.60 meters at 77 meters vertical depth, demonstrating the consistent high-grade nature of the system.

While the high-grade structures show similarities to those at Cariboo, the presence of broader lower-grade mineralization may indicate potential for bulk mining methods. This dual potential for both high-grade underground-style mineralization and open-pit bulk mining opportunities aligns with Osisko's strategy to expand its resource base and extend mine life. National Bank Financial mining analyst Don DeMarco noted that while the exceptional grades are noteworthy, the more important takeaway is the scale and the fact that the target remains open in all directions.

How does this discovery impact Osisko Gold's broader strategy?

Osisko Gold is a Canadian gold mining and exploration company listed on the NYSE and TSXV, primarily focused on advancing its 100%-owned, permitted Cariboo Gold Project. Proserpine is one of several regional targets being tested as part of an exploration campaign aimed at identifying additional deposits to support the main development project. The Cariboo project includes a permitted underground mine and processing complex, with a 2025 feasibility study envisioning a scalable underground operation expected to produce about 1.89 million ounces of gold over a 10-year life.

With all holes that reached target depth intersecting mineralization, Osisko has resumed drilling with three rigs and plans a further 26,500 meters to increase drill density at Proserpine Southeast and begin first-pass drilling at Proserpine Northwest. This aggressive exploration plan underscores the prospect of a sizeable new gold system close to its permitted Cariboo project. The company's recent deep drilling at Cariboo has also extended gold mineralization below 700 meters vertical depth, reinforcing the project’s long-term growth potential. The market responded positively to the news, with the stock jumping 12.2% to $3.83, valuing the company at about $1.2 billion.

Technical analysis of related entities, such as Osisko Gold Royalties, shows mixed signals with a bearish divergence between price and volume, suggesting potential near-term downside despite recent upward momentum. However, the fundamental strength provided by the Proserpine discovery and the advanced stage of the Cariboo project provide a solid foundation for Osisko Gold's future resource growth. The company continues to advance construction work while refining the mine plan and testing extensions to mineralization beyond the current reserve base.