NexGen Energy Ltd. — Proxy Solicitation & Information Statement 2026

Apr 16, 2026

April 16, 2026

Computershare

510 Burrard Street, 3rd Floor

Vancouver BC, V6C 3B9

www.computershare.com

To: All Canadian Securities Regulatory Authorities New York Stock Exchange

Subject: NEXGEN ENERGY LTD.

Dear Sir/Madam:

We advise of the following with respect to the upcoming Meeting of Security Holders for the subject Issuer:

Meeting Type :	Annual General and Special Meeting
Record Date for Notice of Meeting :	May 11, 2026
Record Date for Voting (if applicable) :	May 11, 2026
Beneficial Ownership Determination Date :	May 11, 2026
Meeting Date :	June 30, 2026
Meeting Location (if available) :	Vancouver, BC
Issuer sending proxy related materials directly to NOBO:	No
Issuer paying for delivery to OBO:	Yes

Notice and Access (NAA) Requirements:

NAA for Beneficial Holders	Yes
Beneficial Holders Stratification Criteria:	Not Applicable
NAA for Registered Holders	Yes
Registered Holders Stratification Criteria:	Not Applicable

Voting Security Details:

Description	CUSIP Number	ISIN
COMMON SHARES	65340P106	CA65340P1062

Sincerely,

Computershare

Agent for NEXGEN ENERGY LTD.