Mr. Keith Bodnarchuk reports

COSA ANNOUNCES CLOSING OF UPSIZED C$12 MILLION BOUGHT DEAL PRIVATE PLACEMENT

Cosa Resources Corp. has closed its previously announced bought deal private placement of: (i) 5,835,000 common shares of the company at a price of 60 cents per NFT (non-flow-through) share; (ii) 3,045,000 Saskatchewan charity FT (flow-through common) shares of the company at a price of 99 cents per Saskatchewan charity FT share; (iii) 4.02 million national charity flow-through common shares of the company at a price of 87 cents per national charity FT share; and (iv) 2.86 million flow-through common shares of the company at a price of 70 cents per FT share, for aggregate gross proceeds to the company of $12,014,950.

The offering was led by Velocity Capital Partners, as sole bookrunner, and Haywood Securities Inc., as co-lead underwriter, on behalf of a syndicate of underwriters including Canaccord Genuity Corp.

Cosa's largest shareholder, Denison Mines Corp., participated in the offering pursuant to its pre-emptive and top-up rights under the investor rights agreement between Denison and Cosa dated Jan. 14, 2025. Immediately following the closing of the offering, Denison owns 17.7 per cent of Cosa on a partially diluted basis. Denison is a leading Athabasca basin-focused uranium mining, development and exploration company with a market capitalization of over $4.0-billion. Denison's current focus is advancing the development-stage Wheeler River project, which represents one of the largest undeveloped uranium mining projects in the infrastructure-rich eastern portion of the Athabasca basin.

Each charity FT share and FT share will qualify as a flow-through share within the meaning of the Income Tax Act (Canada), and in respect of the Saskatchewan charity FT shares and FT shares issued to subscribers resident in Saskatchewan, will qualify as an eligible flow-through share as defined in The Mineral Exploration Tax Credit Regulations, 2014 (Saskatchewan).

The company intends to use: (i) the net proceeds from the sale of NFT shares to finance exploration and development, and for additional working capital purposes; and (ii) the gross proceeds from the sale of charity FT shares and FT shares to incur eligible Canadian exploration expenses that qualify as flow-through critical mineral mining expenditures as such terms are defined in the Income Tax Act (Canada), and, in respect of the gross proceeds received from subscribers of the saskatchewan charity FT shares and FT shares resident in Saskatchewan, to incur eligible flow-through mining expenditures pursuant to The Mineral Exploration Tax Credit Regulations, 2014 (Saskatchewan), related to the company's uranium projects in the Athabasca basin, Saskatchewan, on or before Dec. 31, 2027, all as further set out in the amended and restated offering document of the company dated June 4, 2026. All qualifying expenditures will be renounced in favour of the subscribers of charity FT shares and FT shares effective Dec. 31, 2026. In the event that the company does not renounce on or prior to Dec. 31, 2026, qualifying expenditures in amount equal to the gross proceeds of the charity FT shares and FT shares purchased and/or if the amount of the qualifying expenditures is reduced upon assessment or reassessment by the Canada Revenue Agency, the company will indemnify each charity FT share and FT share initial subscriber for the additional income taxes payable by such initial subscriber as a result of the company's failure to renounce the qualifying expenditures or as a result of the reduction.

The NFT shares and charity FT shares were sold in reliance on the listed issuer financing exemption under Section Part 5A.2 of NI 45-106, as amended by Coordinated Blanket Order 45-935, Exemptions from Certain Conditions of the Listed Issuer Financing Exemption, to purchasers. The NFT shares and charity FT shares are not subject to a hold period in Canada, other than 778,400 NFT shares and 384,050 FT shares sold to insiders of the company as further described below, which are subject to a hold period ending Oct. 25, 2026, in accordance with the policies of the TSX Venture Exchange. The FT shares are subject to a hold period in Canada ending Oct. 25, 2026.

In connection with the offering, the company paid the underwriters an aggregate cash commission of $570,747.50 and issued to the underwriters an aggregate of 795,600 non-transferable compensation warrants of the company. Each compensation warrant entitles the holder to acquire one common share in the capital of the company at an exercise price of 60 cents per compensation warrant share until June 24, 2028. The compensation warrants and any compensation warrant shares issued pursuant to the exercise thereof are subject to a hold period ending Oct. 25, 2026.

Certain directors and officers of the company, Denison, and a certain director and officer of Denison, participated in the offering and acquired an aggregate of 778,400 NFT shares and 363,700 FT shares for aggregate gross proceeds of $721,630. The participation of such insiders in the offering constitutes a related party transaction within the meaning of Multilateral Instrument 61-101, Protection of Minority Security Holders in Special Transactions. The company has determined that the transaction is exempt from the formal valuation and minority shareholder approval requirements of MI 61-101 by virtue of the exemptions contained in Section 5.5(a) and Section 5.7(1)(a) of MI 61-101, as neither the fair market value of securities issued to such persons nor the consideration paid by such persons exceeded 25 per cent of the company's market capitalization. The company did not file a material change report in respect of the transaction 21 days in advance of closing of the offering because the details of the offering and insider participation had not been confirmed and the shorter period was necessary in order to permit the company to close the offering in a time frame consistent with usual market practice for transactions of this nature.

The offering remains subject to the final approval of the TSX-V.

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 the acquisition by Denison of 750,000 NFT shares on closing of the offering. Immediately prior to the closing of the offering, Denison had beneficial ownership of, or control and direction over, 20,990,864 common shares in the capital of Cosa and 2,417,679 share purchase warrants, representing 17.7 per cent of issued and outstanding shares, and 13.9 per cent of the issued and outstanding share purchase warrants of Cosa, respectively. Immediately following the closing of the offering, Denison had beneficial ownership of, or control and direction over, 21,740,864 shares and 2,417,679 share purchase warrants, representing 16.2 per cent of issued and outstanding shares, and 13.3 per cent of issued and outstanding share purchase warrants of Cosa, respectively. The NFT shares were acquired 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 between Denison and Cosa dated Nov. 26, 2024, and/or its pre-emptive rights under the investor rights agreement. Further information is available in Cosa's news release dated Jan. 14, 2025, in the early warning report to be filed by Denison under Cosa's profile on SEDAR+ or by contacting Denison, Geoff Smith, vice-president, corporate development and commercial, info@denisonmines.com, Suite 1100, 40 University Ave., Toronto, Ont., M5J 1T1.

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 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.

The company's primary focus through the remainder of 2026 will be drilling at the Murphy Lake North and Darby projects in the eastern Athabasca basin. Drilling at Murphy Lake North will follow up uranium mineralization within an extensive zone of strong structure and hydrothermal alteration at the Cyclone trend. Drilling at Darby will follow up on intersections of anomalous geochemistry, structure and zones of hydrothermal alteration from both winter 2026 drilling and historical drilling.

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.

We seek Safe Harbor.