Slide 1: Corporate Update
Corporate Update May 2026 Pinto Valley, Arizona CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC
Slide 2: Cautionary Notes
Cautionary Notes CAUTIONARY NOTE TO UNITED STATES INVESTORS REGARDING PRESENTATION OF MINERAL RESERVE AND MINERAL RESOURCE ESTIMATES As a British Columbia corporation and a “reporting issuer” under Canadian securities laws, we are required to provide disclosure regarding our mineral properties in ac
Slide 3: Cautionary Notes
Cautionary Notes CAUTIONARY NOTE REGARDING FORWARD LOOKING INFORMATION This document may contain “forward-looking information” within the meaning of Canadian securities legislation and “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 19
Slide 4: Copper in Top-Tier Jurisdictions in the Americas
29 Cu Copper COPPER IN TOP-TIER JURISDICTIONS IN THE AMERICAS Peer-Leading Declining Best-in-Class Strong Financial Copper Growth Cash Costs Mine Build and Position Operating Team +70% to ~375ktpa1 ~30% decrease1 +150 years of experience >$1B liquidity*,2 *Adjusted EBITDA and Available Liquidity are
Slide 5: District-Scale Growth in the Americas
District-Scale Growth in the Americas MANTOS BLANCOS (100%) Production by Region5 Producing Asset Development Stage Asset 2026E Production Open Pit 48-56 13+ year mine life kt Cu U.S. 20,000tpd mill capacity 23% +60ktpa cathode capacity3 Cu Ag Mexico PINTO VALLEY (100%) HQ, Vancouver, Canada 10% Chi
Slide 6: Clear Path to Transformational Growth
Clear Path to Transformational Growth Further organic Cu upside opportunities: • MB Phase II • SD Oxides • MV Phase II • Sierra Norte 500 $3.75 Annual Copper Production (kt) 400 ~375kt $3.00 C1 Cash Cost2 (US$/lb) ~265kt SANTO DOMINGO1 300 $2.25 225kt MV OPTIMIZED1 200 184kt $1.50 164kt MANTOVERDE1
Slide 7: Upcoming 2026 Catalysts
Upcoming 2026 Catalysts Q1 Q2 Q3 Q4 MV-O CONSTRUCTION AND RAMP-UP MV PHASE II & SANTO DOMINGO/SIERRA NORTE EXPLORATION PROGRAMS MANTOS BLANCOS PHASE II PERMIT APPLICATION & STUDY SANTO DOMINGO FID Executing peer-leading copper production growth, with a focus on safety, operational excellence and res
Slide 8: 2026 Production and Cost Guidance
2026 Production and Cost Guidance Delivering reliable results from a portfolio of long-life assets in top-tier jurisdictions FY 2026 Cu Production C1 Cash Costs1 (kt) (US$/lb Cu) Production and cost guidance notes: Sulphide Business • Mantoverde • Planned maintenance: Mantoverde2 64 – 74 $1.25 – $1.
Slide 9: Geopolitical Conflict – Recent Cost Pressures
Geopolitical Conflict – Recent Cost Pressures Supply: our mines continue to operate normally, 2026 Diesel Consumption1 with no direct impacts to our operations Expected consumption (April onwards): ~134M litres Costs: higher input prices putting upward pressure 2026 Sulphuric Acid Consumption3 on co
Slide 10: 2026 Capital Expenditures and Exploration Guidance
2026 Capital Expenditures and Exploration Guidance Investing in a strong foundation of operating assets and a peer-leading growth pipeline Sustaining Capital Expansionary Capital Capital Stripping Total (US$M) (US$M) (US$M) (US$M) Capital Expenditures Mantoverde2 $100 $150 $100 $350 Mantos Blancos $
Slide 11: Balance Sheet Strength & Financial Flexibility
Balance Sheet Strength & Financial Flexibility With Disciplined Approach to Future Growth Net Debt / TTM EBITDA* Available Liquidity*,1 (US$M) Adjusted EBITDA* Sensitivity (US$M) 3.6x 2026E EBITDA 2 Annual EBITDA with MV-O Run-rate Production 2, 3 2, 3 Annual EBITDA with MV-O + Santo Domingo Run-rat
Slide 12: Strong Liquidity & Simplified Debt Structure
Strong Liquidity & Simplified Debt Structure Termed-Out Maturities Provide Financial Flexibility Capstone Balance Sheet Summary (as at March 31, 2026) As at Available US$M (1) Total Facility Size Interest Rate Tenor As at 31-Mar-26 31-Mar-26 Liquidity(4) Attributable At 31-Mar-25 Revolving Credit Fa
Slide 13: Mantoverde
2025/2026 Average Monthly Sulphide Plant Throughput (ktpd) Mantoverde Design throughput: 32 ktpd3 35 37 33 maintenance 34 Planned 33 33 32 32 30 30 Asset Overview 25 Unplanned motor 35-day maintenance strike Location Atacama Region, Chile; ~900m above sea level 20 action 18 18 Ownership Capstone (70
Slide 14: Mantos Blancos
Mantos Blancos Asset Overview 2024 - 2026 Throughput1 Performance (ktpd) Location Antofagasta Region, Chile; ~900m above sea level Confidence in Achieving Design Throughput Rates Ownership Capstone (100%) Planned maintenance Planned and and Chile power unplanned Planned Mine Type Open Pit (operating
Slide 15: Pinto Valley
Pinto Valley Pinto Valley District in Globe-Miami, Arizona Asset Overview Arizona (Globe-Miami), USA; Location ~1,000m above sea level Ownership Capstone (100%) Mine Type Open Pit (operating since 1975) Commodity Cu (primary), Mo/Au (secondary) Product(s) Sulphide concentrate + Grade A copper cathod
Slide 16: Cozamin
Cozamin C1 Cash Costs (US$/lb) 1,2 Asset Overview Location Zacatecas, Mexico; ~2,400m above sea level Strong by-product production and Ownership Capstone (100%) silver prices driving record quarterly Mine Type Underground (operating since 2007) $1.74 $1.78 C1 cash costs1,2 $1.32 Commodity Cu (primar
Slide 17: Expansion & Optionality Across the Portfolio
Expansion & Optionality Across the Portfolio MANTOVERDE – SANTO DOMINGO DISTRICT MV-SD 35km Apart PINTO VALLEY COZAMIN MANTOS BLANCOS MANTOVERDE SANTO DOMINGO Mine Life Extension and Fully Permitted Project; Mine Life Extension and Expansion Opportunities Across our Producing Assets Expansion Opport
Slide 18: Expansion & Optionality Across the Portfolio
Expansion & Optionality Across the Portfolio Project Status MV Optimized Construction underway, construction tie-in in Q3 2026 Near-Term +20kt copper/year incremental production1 Low capital intensity, brownfield expansion Santo Domingo Fully permitted, sanctioning +106kt copper/year incremental pro
Slide 19: Mantoverde Optimized
Mantoverde Optimized A Capital-Efficient Brownfield Expansion 2026 New tailings thickener 2024 2025 pumps Q1 Q2 Q3 Q4 Feasibility Study $176M Approval of Long-Lead Items Initial Capex for Brownfield DIA Permit Expansion Opportunity Detailed Engineering Sanctioning Construction & Tie-Ins (~15 days Q3
Slide 20: Santo Domingo
Key Metrics at a Glance - July 2024 Feasibility Study Santo Domingo 29 Cu Copper 19 Year 106kt $0.28/lb Asset Overview Mine Life Avg. Annual C1 Cash Costs2 Cu Production2 (by-product basis) Location Atacama Region, Chile; low elevation at ~1,000m above sea level 1 Ownership Capstone (75%), Orion Res
Slide 21: Replicating Mine-Building Success in the Region
Replicating Mine-Building Success in the Region Project similarities and application of lessons learned to drive success Mantoverde Santo Domingo Mantoverde Development Project Project Produce sulphide ore with the Produce copper sulphide and iron addition of sulphide concentrator oxide concentrates
Slide 22: Santo Domingo Production and Costs
Santo Domingo Production and Costs Long Mine Life with a Robust Production Profile and First Quartile Costs LOM Production (kt) 200 Copper (kt) Iron Ore (kt) 180 CuEq. Production (kt) 160 Evaluating additional copper production optionality via Santo 140 Domingo oxides and integration of Sierra Norte
Slide 23: Santo Domingo Well-Positioned in Tier-1 District
Santo Domingo Well-Positioned in Tier-1 District Relative Advantage in Both Project Elevation and Access to Key Infrastructure Project Elevation and Distance to Key Infrastructure1,2 Santo Domingo has High Vicuña³ Elevation 5,000 a key strategic advantage from its low elevation and proximity to ke
Slide 24: Santo Domingo Path Forward
Santo Domingo Path Forward Advancing Remaining Workstreams in Parallel In Progress: Completed: In Progress: Engineering & (1) Study Balance Sheet Optimization Published updated Targeting <1.0x net debt to Progress detailed engineering; Feasibility Study for EBITDA (2) leverage and pursue infrastruct
Slide 25: Santo Domingo Illustrative Funding Structure
Santo Domingo Illustrative Funding Structure Prudent Approach to Capital Allocation in Pursuit of Transformational Growth $2.3Bn1 $1.2Bn2 Capstone Q1 2026 Balance Sheet Summary5 Remaining Funding Requirement Consolidated Net Debt6 of $738M Capstone portion of remaining funding 0.7x Net Debt / LT
Slide 26: Achieving District Scale Optimization in the MV-SD District
Achieving District Scale Optimization in the MV-SD District Unlocking a New World-Class Copper District with Additional Value Through Upside Opportunities Targeting +250,000 tonnes per year of low-cost copper production with a significant by-product of premium grade iron ore, with the potential to b
Slide 27: Mantos Blancos Upside Opportunities
Mantos Blancos Upside Opportunities Opportunity Highlights Stage / Impact • Controlled Potential Sulphidation (CPS) • Flotation activator for copper oxides in sulphide • At 20ktpd throughput, opportunity to Continuous circuit expand sulphide Cu production by Improvements • Energy Efficient Pulp Lift
Slide 28: Enhancing the Pipeline Through Exploration
Enhancing the Pipeline Through Exploration MANTOVERDE – SANTO DOMINGO DISTRICT MV-SD 35km Apart SANTO DOMINGO + PINTO VALLEY COZAMIN MANTOS BLANCOS MANTOVERDE SIERRA NORTE Mala Noche Vein SR Gap MNFWZ – Vein 20 MNV West MNFWZ Deep District Growth Study Mine Life Extension Near-Mine Exploration Near-
Slide 29: MV-SD: Exploration Program
MV-SD: Exploration Program Mantoverde Initial Two-Year $25M Exploration Mantoverde & Santo Domingo District1 Program Sierra Norte • Targeting higher copper grades 6 5 N • Exploring new areas adjacent or inside the current Mantoverde pits 4 • Testing high priority targets in the northern area of Nort
Slide 30: MV Initial Two-Year Exploration Program
MV Initial Two-Year Exploration Program Results from Phase 1 Overview of Phase 11: Highlights from Initial Results: 30,000-metres of drilling focused on areas • Higher than expected grades in Brecha Flores sector, where drill intercepts returned copper grades above those predicted adjacent to MV-O P
Slide 31: Santo Domingo and Sierra Norte Exploration Program
Santo Domingo and Sierra Norte Exploration Program Santo Domingo Exploration Potential IOCG type of mineralization with copper, gold, iron and cobalt ~340Mt of sulphide resource not included into reserves Key programs include: 54,700 metre drill program at Opportunity to define an oxide resource i
Slide 32: Three “Geo’s” Constraining Copper Supply Growth
Three “Geo’s” Constraining Copper Supply Growth… LME copper prices gained +40% over 2025, the highest annual increase since 2009 • Declining Cu grades • More complex mining • Security of supply • Lack of new copper methods (deeper • Rising geopolitical discoveries underground mines, tensions • Lack
Slide 33: …While New Sources of Copper Demand Emerge
…While New Sources of Copper Demand Emerge Robust “traditional” demand amplified by emerging global trends • Population growth • Renewable power • AI & data centres • Urbanization • Electric vehicles • Onshoring of supply • Industrialization • Industry electrification chains • Increasing living • Gr
Slide 34: Capstone Copper – Capital Structure
Capstone Copper – Capital Structure Share Metrics Analyst Coverage Total Shares Outstanding1 764 million Barrenjoey J.P. Morgan Total Shares Outstanding (Fully Diluted)1 770 million Bradesco BBI Macquarie Shares Held as ASX CDIs2 174 million BMO Capital Markets Moelis & Company Market Cap3 US$6.5Bn
Slide 35: Copper in Top-Tier Jurisdictions in the Americas
29 Cu Copper COPPER IN TOP-TIER JURISDICTIONS IN THE AMERICAS Peer-Leading Declining Best-in-Class Strong Financial Copper Growth Cash Costs Mine Build and Position Operating Team ~70% to ~375ktpa1 ~30% decrease1 +150 years of experience >$1B liquidity*,2 *Adjusted EBITDA and Available Liquidity are
Slide 36: Q1 2026 Actuals
Q1 2026 Actuals Q1 2026 Cu Production C1 Cash Costs1 Quarterly Adjusted EBITDA 1 (US$M) and (tonnes) (US$/lb Cu) Adjusted EBITDA Margin (%) Sulphide Business 350 60% Mantoverde2 13,733 $1.33 Mantos Blancos 10,501 $2.79 50% 300 Pinto Valley 10,711 $3.46 50% 45% Cozamin 5,930 $0.71 42% 250 40% Total S
Slide 37: 2022-2025: Executing Transformational Growth
2022-2025: Executing Transformational Growth 2022 2023 2024 2025 Annual Copper Production (kt) and Cu C1 Cash Cu C1 Cash Cu C1 Cash Cu C1 Cash C1 Cash Costs (US$/lb) 1 Production Costs1 Production Costs1 Production Costs1 Production Costs1 250 $3.00 (tonnes) (US$/lb Cu) (tonnes) (US$/lb Cu) (tonnes)
Slide 38: Consolidated Estimated Mineral Resources
Consolidated Estimated Mineral Resources NOTES: Mineral Resources take into account mining activities to the effective date, where applicable and are reported insitu, using the 2014 CIM Definition Standards. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Slide 39: Consolidated Estimated Mineral Reserves
Consolidated Estimated Mineral Reserves MINERAL RESERVES CONTAINED METAL TCu SCu ICu Zn Pb Mo Ag Au Fe Cu Zn Pb Mo Ag Au Fe3 Category kt % % % % % % g/t g/t % kt kt kt kt koz koz Mt Pinto Valley1 Proven 249,491 0.32 - - - - 0.007 - - - 803 - - 16 - - - 31-Dec-2025 Probable 50,724 0.30 - - - - 0.005
Slide 40: Sierra Norte
Sierra Norte Historical Mineral Resources Notes: Category Tonnes (Mt) CuT % CuS % Copper (kt) The Historical Mineral Resource was derived from the report “Actualización del Modelo Geológico y de la Estimación de Recursos Minerales del Proyecto Diego de Almagro” completed by Amec Foster Carmen-Paulin
Slide 41: General Enquiries
GENERAL ENQUIRIES Capstone Copper Corp. 2100 – 510 West Georgia Street Vancouver, BC - V6B 0M9 Capstonecopper.com info@capstonecopper.com +1-604-684-8894 Toll-free NA 1-866-684-8894 MEDIA & INVESTOR ENQUIRIES Daniel Sampieri, Vice President, Investor Relations +1-437-788-1767, Toronto, ON Michael Sl