Mr. Keith Bodnarchuk reports

COSA APPOINTS JUSTIN RODKO AS VP CORPORATE DEVELOPMENT AND ISSUES SHARES TO DENISON

Cosa Resources Corp. has promoted Justin Rodko to vice-president, corporate development. Additionally, the company announces the issuance of common shares to its largest shareholder and joint venture partner Denison Mines Corp. (Toronto Stock Exchange: DML) (NYSE American: DNN) pursuant to the acquisition agreement between Cosa and Denison dated Nov. 26, 2024.

Mr. Rodko is a professional geoscientist with over a decade of experience exploring for uranium in Saskatchewan's Athabasca basin. Before joining Cosa in 2023, Mr. Rodko previously held the role of senior geologist at IsoEnergy where he played key roles in expanding IsoEnergy's Athabasca portfolio and the discovery of the Hurricane deposit. In recognition of the Hurricane discovery, Mr. Rodko was awarded the AME 2022 Colin Spence Award for excellence in global mineral exploration alongside Cosa team members Steve Blower, Andy Carmichael and Craig Parry. Since joining Cosa, Mr. Rodko has made significant contributions to Cosa's corporate strategy and developments, including the completion of a transformative transaction with Denison in January of 2025, financings, market presence, and strategic divestments and continuing initiatives.

Keith Bodnarchuk, president and chief executive officer, commented: "Justin's appointment to VP of corporate development is in recognition of the enormous role he's played since 2023 in building Cosa to its current form. He brings a unique combination of capital market skills and technical knowledge which includes his role as a key member of IsoEnergy's discovery team for the Hurricane deposit. We are proud to have Justin as a team member, and I am thrilled to work alongside Justin, Andy, Darren and the rest of our world-class uranium exploration team as we continue to pursue the next great uranium discovery. We look forward to updating the market shortly on our detailed drill plans for the Darby and Murphy Lake North joint ventures prior to embarking on Cosa's largest and most significant drilling campaign to date."

Deferred consideration shares

The company announces that it has issued an aggregate of 1.96 million common shares to Denison as partial satisfaction of the deferred consideration payable under the acquisition agreement. The deferred consideration shares were issued at a deemed price of 38.91 cents per share. Following this issuance, deferred consideration with an aggregate value of approximately $1,487,364 remains payable to Denison, to be satisfied through the future issuance of additional common shares in accordance with the terms of the acquisition agreement. The deferred consideration shares are subject to a statutory hold period of four months and a day.

Denison will be filing an early warning report, under National Instrument 62-103 -- The Early Warning System and Related Take-Over Bid and Insider Reporting Issues in respect of its acquisition of the 1.96 million deferred consideration shares. Prior to the issuance of the deferred consideration shares by Cosa, Denison held 19,030,864 shares and 2,417,679 common share purchase warrants, representing 16.85 per cent of Cosa on a partially diluted basis. Immediately after giving effect to the offering, Denison had beneficial ownership of, or control and direction over, 20,990,864 shares, representing 18.26 per cent of the issued and outstanding shares of Cosa as of the date hereof and 2,417,679 common share purchase warrants, representing 9.81 per cent of Cosa's issued and outstanding warrants. The deferred consideration shares were acquired pursuant to Denison's rights under the acquisition agreement and held by Denison for investment purposes. Denison intends to review, on a continuous basis, various factors related to its investment in Cosa, and may decide to acquire or dispose of additional securities of Cosa as future circumstances may dictate, including pursuant to the exercise of warrants, the terms of the acquisition agreement and/or its pre-emptive rights under the investor rights agreement between Denison and Cosa. Further information will be available in the early warning report to be filed by Denison under Cosa's profile on SEDAR+.

About Cosa Resources Corp.

Cosa Resources is a Canadian uranium exploration company operating in Northern Saskatchewan. The portfolio comprises roughly 237,000 hectares across multiple underexplored 100-per-cent-owned-and-Cosa-operated joint venture projects in the Athabasca basin region, the majority of which reside within or adjacent to established uranium corridors.

In January of 2025, the company entered a transformative strategic collaboration with Denison Mines (TSX: DML) (NYSE American: DNN) that has secured access to several additional highly prospective eastern Athabasca uranium exploration projects. As Cosa's largest shareholder, Denison gains exposure to Cosa's potential for exploration success and its pipeline of uranium projects.

Cosa's award-winning management team has a record of success in Saskatchewan. In 2022, members of the Cosa team were awarded the AME Colin Spence Award for the discovery of the Hurricane uranium deposit. Cosa personnel led teams or had integral roles in the discovery of Denison's Gryphon deposit and held key roles in the founding of both NexGen and IsoEnergy.

The company's focus throughout 2026 is drilling at the Darby and MLN projects in the eastern Athabasca basin. Both projects are operated by Cosa and are 70/30 joint ventures between Cosa and Denison, respectively. Drilling at Darby will evaluate target areas with anomalous uranium, clay alteration and historical mineralization intersected nearby. Drilling at MLN will follow up 2025 drilling which intersected broad zones of structurally controlled alteration over roughly two kilometres of strike length.

We seek Safe Harbor.