(All dollar amounts are expressed in Canadian dollars, unless stated otherwise) HIGHLIGHTS Q4 2025 (at December 31, 2025) Financial: ~$422.3 million in cash and cash equivalents; sold 3,970 ounces of gold from small-scale mining activities at the Tintic Project Financing: Completed a private placement financing for ~$82.5 million in gross proceeds Cariboo Gold Project: Released new infill drill results from the ongoing program in the Lowhee Zone and commenced a multi-faceted surface exploration program targeting new discoveries; pre-construction activities continued to advance, including the water treatment plant, underground development waste rock storage facility, sediment control pond, site camp upgrade and other critical infrastructure Corporate: Announced sale of the San Antonio Gold Project; Appointed Scott Smith as VP, Exploration Subsequent to Q4 2025 Financial: Received ~$24.9 million in proceeds from a warrants exercise Financing: Completed prospectus offering of common shares for ~US$143.8 million in gross proceeds Cariboo Gold Project: Resumed planned site activities in accordance with a phased reopening plan following a temporary suspension due to a fatal incident that occurred on January 22, 2026; entered into a project and construction management services agreement with JDS Energy & Mining; released new infill drill results from the ongoing Lowhee Zone (aggregate total 11,025 metres, or ~80% of planned program) Corporate: Completed sale of the San Antonio Gold Project; appointed Sarah Harrison as VP, Permitting & Compliance; announced the Company's inclusion in the VanEck Junior Gold Miners ETF (GDXJ) MONTREAL, March 27, 2026 (GLOBE NEWSWIRE) -- Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") reports its financial and operating results for the three and twelve months ended December 31, 2025 ("Q4 2025" and "2025", respectively). Q4 2025 HIGHLIGHTS Operating, Financial and Corporate Updates: As of December 31, 2025, the Company had approximately $422.3 million in cash and cash equivalents.