Osisko Development Corp., a North American gold development company, completed offerings totalling US$300 million aggregate principal amount of 4.125 percent convertible senior notes due 2031. The financing comprised a US$225-million base offering to qualified institutional buyers under Rule 144A, which closed on May 26, 2026, and an additional US$75 million that closed on May 29, 2026, consisting of US$25 million issued on the full exercise of the initial purchasers' option and US$50 million acquired by Double Zero Capital, LP in a concurrent non-brokered private placement. Double Zero, an affiliate and insider of the company, made its investment pursuant to its pre-emptive right under an investor rights agreement effective August 15, 2025, in order to maintain its pro rata ownership interest in Osisko Development; its participation was treated as a related party transaction under Multilateral Instrument 61-101. The notes are senior unsecured obligations bearing interest at 4.125 percent payable semi-annually, maturing June 15, 2031, and were initially convertible at 272.1088 common shares per US$1,000 principal amount, implying a conversion price of approximately US$3.68 per share, a 25 percent premium to the NYSE closing price on May 20, 2026. A portion of the net proceeds funded cash-settled capped call transactions costing approximately US$40.2 million, effectively increasing the conversion premium to 100 percent. Net proceeds, estimated at roughly US$290 million, are expected to be used for development of the Cariboo Gold Project in British Columbia and for general corporate purposes. Cantor Fitzgerald & Co. acted as structuring advisor and sole book-running manager for the base offering.