Good Energy

for Generations

Investor overview: building one of the world’s largest sources of uranium

TSX · NYSE: NXE · ASX: NXG | October 2026

CORPORATE PRESENTATION | FORWARD LOOKING STATEMENTS

Forward-Looking Information

The information contained herein contains "forward-looking statements" within the meaning of applicable United States securities laws and regulations and "forward-looking information" within the meaning of applicable Canadian securities legislation. "Forward-looking information" includes, but is not limited to, statements with respect to mineral reserve and mineral resource estimates, the 2021 Arrow Deposit, Rook I Project and estimates of uranium production, grade and long-term average uranium prices, anticipated effects of completed drill results on the Rook I Project, planned work programs and development activities and budgets, Canadian Nuclear Safety Commission and other approvals, completion of further site investigations and engineering work to support basic engineering of the project and expected outcomes. Generally, but not always, forward-looking information and statements can be identified by the use of words such as "plans", "expects", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", or "believes" or the negative connotation thereof or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" or the negative connotation thereof. Statements relating to "mineral resources" are deemed to be forward-looking information, as they involve the implied assessment that, based on certain estimates and assumptions, the mineral resources described can be profitably produced in the future.

Forward-looking information and statements are based on the then current expectations, beliefs, assumptions, estimates and forecasts about NexGen's business and the industry and markets in which it operates. Forward-looking information and statements are made based upon numerous assumptions, including among others, that the mineral reserve and resources estimates and the key assumptions and parameters on which such estimates are based are as set out in this presentation and the technical report for the property , the results of planned exploration activities are as anticipated, the price and market supply of uranium, the cost of planned exploration activities, that financing will be available if and when needed and on reasonable terms, that third party contractors, equipment, supplies and governmental and other approvals required to conduct NexGen's planned exploration activities will be available on reasonable terms and in a timely manner and that general business and economic conditions will not change in a material adverse manner. Although the assumptions made by the Company in providing forward looking information or making forward looking statements are considered reasonable by management at the time, there can be no assurance that such assumptions will prove to be accurate in the future.

Forward-looking information and statements also involve known and unknown risks and uncertainties and other factors, which may cause actual results, performances and achievements of NexGen to differ materially from any projections of results, performances and achievements of NexGen expressed or implied by such forward-looking information or statements, including, among others, the existence of negative operating cash flow and dependence on third party financing, uncertainty of the availability of additional financing, the risk that pending assay results will not confirm previously announced preliminary results, conclusions of economic valuations, the risk that actual results of exploration activities will be different than anticipated, the cost of labour, equipment or materials will increase more than expected, that the future price of uranium will decline or otherwise not rise to an economic level, the appeal of alternate sources of energy to uranium-produced energy, that the Canadian dollar will strengthen against the U.S. dollar, that mineral resources and reserves are not as estimated, that actual costs or actual results of reclamation activities are greater than expected, that changes in project parameters and plans continue to be refined and may result in increased costs, of unexpected variations in mineral resources and reserves, grade or recovery rates or other risks generally associated with mining, unanticipated delays in obtaining governmental, regulatory or First Nations approvals, risks related to First Nations title and consultation, reliance upon key management and other personnel, deficiencies in the Company’s title to its properties, uninsurable risks, failure to manage conflicts of interest, failure to obtain or maintain required permits and licences, risks related to changes in laws, regulations, policy and public perception, as well as those factors or other risks as more fully described in NexGen’s Annual Information Form dated March 3, 2026 filed with the securities commissions of all provinces and territories of Canada and in NexGen’s 40-F filed with the United States Securities and Exchange Commission, which are available on SEDAR+ at www.sedarplus.ca and Edgar at www.sec.gov.

Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in the forward-looking information or statements or implied by forward-looking information or statements, there may be other factors that cause results not to be as anticipated, estimated or intended. Readers are cautioned not to place undue reliance on forward-looking information or statements due to the inherent uncertainty thereof. There can be no assurance that forward-looking information and statements will prove to be accurate, as actual results and future events could differ materially from those anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking statements or information. The Company undertakes no obligation to update or reissue forward-looking information as a result of new information or events except as required by applicable securities laws.

This presentation includes Mineral Reserves and Mineral Resources classification terms that comply with reporting standards in Canada and the Mineral Reserves and the Mineral Resources estimates are made in accordance with NI 43-101. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. These standards differ from the requirements of the Securities and Exchange Commission (“SEC”) set the SEC's rules that are applicable to domestic United States reporting companies. Consequently, Mineral Reserves and Mineral Resources information included in this presentation is not comparable to similar information that would generally be disclosed by domestic U.S. reporting companies subject to the reporting and disclosure requirements of the SEC Accordingly, information concerning mineral deposits set forth herein may not be comparable with information made public by companies that report in accordance with U.S. standards.

All material scientific and technical information in this presentation is derived from the Company’s independent feasibility study (the “Rook I FS Technical Report” or the “FS”) entitled “Arrow Deposit, Rook I Project, Saskatchewan, Nl 43-101 Technical Report on Feasibility Study dated March 10, 2021 filed under the Company’s profile on SEDAR+ at www.sedarplus.ca and on EDGAR at www.sec.gov. For details of the Rook I Project, including the key assumptions, parameters and methods used to estimate the Mineral Resources described in this Presentation, please refer to the Rook I FS Technical Report.

All scientific and technical information in this presentation has been reviewed and approved by Mr. Simon Allard, P.Eng, Vice President, Commercial, and Mr. Jason Craven, P.Geo., Vice President, Exploration for NexGen. Mr. Allard approved the scientific and technical information related to operational matters contained in this MD&A and Mr. Craven approved the scientific and technical information related to exploration matters. Each of Mr. Allard and Mr. Craven is a qualified person for the purposes of NI 43-101.

NexGen Energy | Investor Overview | October 2026

NEXGEN AT A GLANCE

The world’s largest uranium source in construction

NexGen is building the Rook I mine in Saskatchewan, Canada. Uranium is the fuel for nuclear power plants. Once in production, Rook I could supply about 20% of global supply and 50% of Western supply.

Up to 30M lbs

of uranium a year

~20%

of global primary supply¹

>50%

of Western supply¹

C$970M

cash on hand (June 30, 2026)

1 Based on Rook I potential production from the 2021 Feasibility Study (FS) and Centre for International Economics modeling. The current mine plan and economics remain those in the 2021 FS.

NexGen Energy | Investor Overview | October 2026

THE STORY ON ONE PAGE

Four reasons NexGen matters

Demand is rising

Nuclear power is expanding worldwide, and AI data centres need large amounts of reliable, carbon-free power.

Supply is falling short

New mines take 15–20 years to develop. The yearly uranium shortfall could reach 335M lbs by 2040.

A world-scale asset

Rook I could produce up to 30Mlbs a year — about 20% of global primary supply — from Canada.

Built to benefit from price

Priced at market on delivery: maximum leverage to rising price of uranium.

NexGen Energy | Investor Overview | October 2026

THE MARKET: DEMAND

Nuclear power is growing again, and AI adds fuel

441

reactors operating today

Together they produce about 10% of the world’s electricity.

reactors under construction

Adding ~88 GW, a ~20% increase in global nuclear capacity by the early 2030s, and 35–44Mlbs of new yearly uranium demand.¹

60Mlbs

a year by 2030

Uranium the U.S. alone would need if its AI data-centre build-out were fully powered by nuclear.³

38 countries have pledged to triple nuclear capacity by 2050 — from 380 GW to 1,200 GW.² Each gigawatt needs about 200 tonnes of uranium a year.

1 World Nuclear Association (WNA) 2 WNA World Nuclear Fuel Report 2025 (Sept 5, 2025) 3 McKinsey & Co, Aug 2025, “Scaling bigger, faster, cheaper data centers with smarter designs”

NexGen Energy | Investor Overview | October 2026

THE MARKET: SUPPLY

Mines can’t keep up with demand

335M lbs

Projected yearly shortfall by 2040, about 63% of demand.¹

15–20 yrs

Typical time from discovering a deposit to producing from it, so supply can’t respond quickly.

3×

Mine supply must more than triple to meet ~530M lbs of 2040 demand.

1 WNA, The Nuclear Fuel Report (Sept 2025), Section 5.7, Figs 5.11–5.13 and Table 5.13 (Upper Scenario). Bar heights are derived from WNA’s published gap figures and rounded.

NexGen Energy | Investor Overview | October 2026

THE MARKET: WHERE URANIUM COMES FROM

The West relies on foreign uranium

45%

gap between what OECD* countries use and what they produce.¹ ²

>90%

of Western supply is tied up in long-term contracts below market prices.

<1%

of uranium is produced domestically in the U.S., UK and Europe.

Rook I helps diversify the world’s supply away from geopolitically risky sources, but more new supply is still urgently needed.

*OECD: Organisation for Economic Co-operation and Development, mostly advanced economies incl. the U.S., Canada, UK and much of Europe. 1 OECD, Uranium 2022: Resources, Production and Demand 2 WNA World Nuclear Fuel Report 2023, Upper Case

NexGen Energy | Investor Overview | October 2026

THE ASSET: ROOK I

One mine. About 20% of the world’s uranium.

Where

Southwestern Athabasca Basin, northern Saskatchewan, Canada

How much

Up to 30Mlbs of uranium a year, enough to power cities and nations

Status

In construction with first production targeted in Q3 2030

Upside

Active exploration and discovery at Patterson Corridor East (PCE)

NexGen Energy | Investor Overview | October 2026

THE UPSIDE: A NEW DISCOVERY

A promising new discovery next door

NexGen has found more high-grade uranium at Patterson Corridor East (PCE), just 3.5 km from the Rook I mine. PCE is not in today’s mine plan, so it is potential upside on top of it.

3.5 km

Arrow deposit

Rook I mine, in construction

PCE

New discovery, being drilled

7 in 10

holes drilled at PCE have found uranium, many of them high-grade (rich in uranium)

930m

the depth uranium now reaches, and the high-grade zone is still growing

5 drills

at work in 2026, as part of a 45,500m drilling program

Early stage: no economic analysis has been done, these results don’t show economic viability, and future resource or reserve estimates need more drilling and technical work. Similarities to Arrow are for context only. 79 of 115 holes mineralized; 54 high-grade (>10,000 counts per second on a radiation counter). See news releases dated Aug 25, May 7, Apr 22 and Jan 15, 2026, and July 29, May 27 and Mar 24, 2025.

NexGen Energy | Investor Overview | October 2026

HOW NEXGEN PLANS TO SELL

Designed to capture rising uranium prices

Priced when delivered

Contracts use market-related prices at the time of delivery, so NexGen shares in higher future prices.

Volume-based contracts

Customers commit to quantities; 11.7M lbs are already committed at market-related pricing from commercial production.

Low costs as a cushion

Low operating costs are designed to protect margins through any price cycle.

Illustrative: what NexGen would receive on its first sales commitments*

If the uranium price is…	NexGen receives…
US$80/lb	US$79/lb
US$100/lb	US$99/lb
US$150/lb	US$141/lb
US$175/lb	US$150/lb

Same each year, 2030–2034, on 1M lbs a year.

*Initial commitments of 5M lbs (1M lbs/yr over 5 years). Rounded; includes applicable discounts; excludes escalation, ancillary commissions and delivery costs and the August 2025 contract for an additional 5M lbs. Illustrative only, not a forecast. See press releases of Dec 4, 2024 and Aug 6, 2025.

NexGen Energy | Investor Overview | October 2026

THE IMPACT

What 30 million pounds a year means

Illustrative annual impact of Rook I at full production*

46M

homes

powered with carbon-free energy, about 1 in 3 homes in the U.S.

70M

cars

the equivalent taken off the road, every single year

300M+

tonnes of CO₂

displaced each year. Not offset. Displaced.

*Based on the 2021 FS production schedule of ~30M lbs U₃O₈ a year (Years 1–5). Illustrative only; does not imply any increase to reserves or mine life; subject to permitting, financing, operating performance and market conditions; excludes construction-phase impacts.

NexGen Energy | Investor Overview | October 2026

INVESTING IN PEOPLE

Built with and for local communities

Rook I is ~150 km north of La Loche and the Clearwater River Dene Nation (combined population 4,500+). NexGen hires locally and funds training that builds skills beyond mining.¹

94%

of 2024 Rook I procurement spend (C$56.6M) went to local and Indigenous-partnered businesses

1 NexGen 2024 Sustainability Report

82%

of Rook I site employees in 2024 were from the local priority area

500+

local students in company-funded training programs since 2023

NexGen Energy | Investor Overview | October 2026

THE TEAM

Proven Leadership

Leigh Curyer

CEO, President & Director

Travis McPherson

Chief Commercial Officer

Ryan Podrasky, CPA

Chief Financial Officer

Monica Kras

VP, Corporate Development

Luke Moger

VP, Environment, Permitting, Licensing

Dylan Smart

VP, Regional Development

Jason Craven

VP, Exploration

Expertise across the full mining cycle: permitting, project financing, construction and operations.

3,140+

years of combined experience

207

people across leadership and project teams

$20B+

in projects delivered by the project team

Liquidity & Strategic Assets

C$970 M

Cash1

PROJECT FINANCING OPTIONALITY:

Prepayments, Strategic Partners, Project Debt and others

~30%

Iso Energy Ltd. Ownership (C$241M)2

2.7 Mlbs

of U3O8 Strategic Uranium Inventory

Shares Issued

677 M

Options

47 M

Fully Diluted4

~724 M

Q2/26 Average Daily Trading Volume5

C$153 M

Supports a fully funded path to production with supportive shareholder alignment.

OWNERSHIPS OF JUNE 30, 20266

1 Approximate cash balance as per June 30st 2026

2 Based on IsoEnergy market capitalization as of September 25, 2026

3 On May 8, 2024 the Company entered into a binding term sheet with MMCap International Inc. SPC for purchase of 2,702,410 lb of natural uranium concentrate for an aggregate purchase price of US$250M based on the 5-day average UxC spot price. This transaction closed on May 28th 2024.

4 Inclusion of the new US$110M 2023 Debentures and the US$250M 2024. Debentures, converted at US$6.76 and US$10.73, respectively, would bring the number to fully diluted shares to 757,427,218. Assumes potential conversion of the US$110M 2023 Debentures converted at US$6.76 (~16M), and of the US$250M 2024 Debentures converted at US$10.73 (~23M)

5 Traded on the TSX, NYSE and ASX for Q2 2026

6 Management ownership figures include shares held by Mega Uranium Ltd. For clarity, these shares are not owned or controlled by NexGen management or insiders, as per SEDI filings.

7 Rounded to the nearest percentage. Americas includes USA and Latin America, Australia includes Asia Pacific.

Retail

Institutional