NorthIsle Copper and Gold Inc. filed a prospectus supplement dated March 2, 2026 to its February 25, 2026 short form base shelf prospectus, qualifying a best-efforts public offering of up to 32,787,000 common shares at $3.05 per share for maximum gross proceeds of $100,000,350. The company also granted the agents an over-allotment option for up to 2,229,700 additional shares, which would bring total gross proceeds to $106,800,935 if fully exercised. Concurrently, NorthIsle intends to complete a brokered private placement of up to 1,050,000 common shares for $3,202,500 and a non-brokered private placement of 1,639,300 shares to Wheaton Precious Metals Corp. for $4,999,865, collectively the Concurrent Private Placements. Net proceeds from the maximum offering and Concurrent Private Placements are expected to range from approximately $102.7 million to $109.2 million after commissions and expenses, depending on exercise of the over-allotment option, and will fund the advancement of the North Island Project and general corporate purposes. On February 26, 2026, the last trading day prior to the offering announcement, NorthIsle's TSXV-listed shares closed at C$3.37, while the OTCQX price was US$2.43, equivalent to approximately C$3.37.

Blake, Cassels & Graydon LLP is acting as Canadian counsel and Paul, Weiss, Rifkind, Wharton & Garrison LLP as United States counsel for the company, while McInnes Cooper is counsel to the agents. The accompanying base shelf prospectus qualifies up to $250,000,000 in various securities for future issuance.