NexGen Energy Ltd. Closes A$1 Billion (C$950 Million) Global Equity Offering

Press Release

Vancouver, British Columbia–(- October 16, 2025) – NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) (“NexGen” or the “Company”) is pleased to announce it has closed its previously announced global equity offering for aggregate gross proceeds of approximately A$1 billion (C$950 million)¹, consisting of:

• 33,112,583 common shares of the Company (“North American Shares”) sold on a bought deal basis through a syndicate of underwriters led by Merrill Lynch Canada Inc. (the “Lead Underwriter”) and including Stifel Nicolaus Canada Inc., J.P. Morgan Securities Canada Inc., BMO Nesbitt Burns Inc., National Bank Financial Inc., RBC Dominion Securities Inc., and Canaccord Genuity Corp. (collectively, with the Lead Underwriter, the “Underwriters”) at a price of C$12.08 per share for gross proceeds of approximately C$400 million (the “North American Offering”); and

• 45,801,527 common shares of the Company (the “Australian Shares”), settled in the form of CHESS Depository Interests (“CDIs”), and placed with institutional investors on an underwritten basis by Aitken Mount Capital Partners Pty Ltd (ABN 39 169 972 436) (the “Australian Underwriter”) acting as sole underwriter, joint lead manager and joint bookrunner, and Canaccord Genuity (Australia) Limited (ACN 075 071 466) acting as joint lead manager and joint bookrunner at a price of A$13.10 per CDI² for gross proceeds of approximately A$600 million (the “Australian Offering” and together with the North American Offering, the “Offering”).

The Company intends to use the net proceeds from the Offering to advance engineering of the Rook I Project, for Rook I pre-production capital costs and for general corporate purposes.

The CDIs, and underlying Australian Shares, were issued without disclosure under the Australian Corporations Act 2001 (Cth) (the “Australian Corporations Act”) to “sophisticated investors” and “professional investors” (within the meaning of sub-sections 708(8) and 708(11) of the Australian Corporations Act) and investors in other jurisdictions that may lawfully participate. The CDIs and underlying Australian Shares have not been registered under the U.S. Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration thereunder or an applicable exemption from the registration requirements thereof.

This news release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of the North American Shares, Australian Shares or CDIs in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of that jurisdiction.

Farris LLP acted as legal counsel to the Company in relation to the Offering. Dorsey Whitney LLP and Allens acted as legal counsel to the Company in relation to the North American Offering and the Australian Offering, respectively. Blake, Cassels & Graydon LLP and Skadden, Arps, Slate, Meagher & Flom LLP acted as legal counsel to the Underwriters in relation to the North American Offering. Gilbert + Tobin acted as legal counsel to the Australian Underwriter in relation to the Australian Offering.

About NexGen

NexGen is a British Columbia corporation with a focus on the acquisition, exploration and development of Canadian uranium projects. NexGen has a highly experienced team of uranium industry professionals with a successful track record in the discovery of uranium deposits and in developing projects through discovery to production. NexGen owns a portfolio of prospective uranium exploration assets in the Athabasca Basin, Saskatchewan, Canada, including a 100% interest in Rook I, location of the Arrow Deposit discovered in February 2014 which is in development.

For additional information and media inquiries:

Leigh Curyer
Chief Executive Officer
NexGen Energy Ltd.
+1 604 428 4112
lcuryer@nxe-energy.ca

Travis McPherson
Chief Commercial Officer
NexGen Energy Ltd.
+1 604 428 4112
tmcpherson@nxe-energy.ca

Monica Kras
Vice President, Corporate Development
NexGen Energy Ltd.
+44 (0) 7307 191933
mkras@nxe-energy.ca

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