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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Corporate Update November 2025 Santo Domingo, Chile
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Cautionary Notes 2 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 accordance with Canadian National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“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. In accordance with NI 43-101, we use the terms mineral reserves and resources as they are defined in accordance with the CIM Definition Standards on mineral reserves and resources (the “CIM Definition Standards”) adopted by the Canadian Institute of Mining, Metallurgy and Petroleum. In particular, the terms “mineral reserve”, “proven mineral reserve”, “probable mineral reserve”, “mineral resource”, “measured mineral resource”, “indicated mineral resource” and “inferred mineral resource” used in this annual information form and the documents incorporated by reference herein and therein, are Canadian mining terms defined in accordance with CIM Definition Standards. These definitions differ from the definitions in the disclosure requirements promulgated by the SEC. Accordingly, information contained in this annual information form and the documents incorporated by reference herein may not be comparable to similar information made public by U.S. companies reporting pursuant to SEC disclosure requirements. United States investors are also cautioned that while the SEC will now recognize “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources”, investors should not assume that any part or all of the mineralization in these categories will ever be converted into a higher category of mineral resources or into mineral reserves. Mineralization described using these terms has a greater amount of uncertainty as to their existence and feasibility than mineralization that has been characterized as reserves. Accordingly, investors are cautioned not to assume that any “measured mineral resources”, “indicated mineral resources”, or “inferred mineral resources” that we report are or will be economically or legally mineable. Further, “inferred resources” have a greater amount of uncertainty as to their existence and as to whether they can be mined legally or economically. Therefore, United States investors are also cautioned not to assume that all or any part of the inferred resources exist. In accordance with Canadian rules, estimates of “inferred mineral resources” cannot form the basis of feasibility or other economic studies, except in limited circumstances where permitted under NI 43-101. CURRENCY All amounts are in US$ unless otherwise specified. Non-GAAP and Other Performance Measures “C1 cash costs”, “cash cost”, “adjusted EBITDA”, “adjusted EPS”, “operating cash flow before changes in working capital”, “adjusted net income”, “net debt”, “net cash”, “attributable net debt/net cash”, “all-in sustaining costs”, “all-in costs”, “available liquidity”, “realized copper price per pound”, “expansion capital” and “sustaining capital” are Alternative Performance Measures. Alternative performance measures are furnished to provide additional information. These non-GAAP performance measures are included in this presentation because these statistics are key performance measures that management uses to monitor performance, to assess how the Company is performing, to plan and to assess the overall effectiveness and efficiency of mining operations. These performance measures do not have a standard meaning within IFRS and, therefore, amounts presented may not be comparable to similar data presented by other mining companies. These performance measures should not be considered in isolation as a substitute for measures of performance in accordance with IFRS. For full information, please refer to the Company’s latest Management Discussion and Analysis published on its Financial Reporting webpage or on SEDAR+. COMPLIANCE WITH NI 43-101 Unless otherwise indicated, Capstone Copper has prepared the technical information in this document (“Technical Information”) based on information contained in the technical reports, Annual Information Form and news releases (collectively the “Disclosure Documents”) available under Capstone Copper’s company profile on SEDAR+ at www.sedarplus.ca. Each Disclosure Document was prepared by or under the supervision of a qualified person (a “Qualified Person”) as defined in National Instrument 43-101 – Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators (“NI 43-101”). Readers are encouraged to review the full text of the Disclosure Documents which qualifies the Technical Information. Readers are advised that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. The Disclosure Documents are each intended to be read as a whole, and sections should not be read or relied upon out of context. The Technical Information is subject to the assumptions and qualifications contained in the Disclosure Documents. Disclosure Documents include the National Instrument 43-101 technical reports titled "Mantoverde Mine, NI 43-101 Technical Report and Feasibility Study, Atacama Region, Chile" effective July 1, 2024, “Santo Domingo Project, NI 43-101 Technical Report and Feasibility Study Update, Atacama Region, Chile” effective July 31, 2024, "NI 43-101 Technical Report on the Cozamin Mine, Zacatecas, Mexico" effective January 1, 2023, "Mantos Blancos Mine NI 43-101 Technical Report Antofagasta / Región de Antofagasta, Chile" effective November 29, 2021, and “NI 43-101 Technical Report on the Pinto Valley Mine, Arizona, USA” effective March 31, 2021. The disclosure of Scientific and Technical Information in this document was reviewed and approved by Peter Amelunxen, P.Eng., Senior Vice President, Technical Services (technical information related to project updates at Santo Domingo and Mineral Resources and Mineral Reserves at Mantoverde), Clay Craig, P.Eng., Director, Mining & Strategic Planning (technical information related to Mineral Reserves at Pinto Valley and Cozamin), and Cashel Meagher, P.Geo., President and Chief Operating Officer (technical information related to Mineral Reserves and Resources at Mantos Blancos) all Qualified Persons under NI 43-101. ADDITIONAL REFERENCE MATERIALS Refer to the Company’s news releases of October 30, 2025, and MD&A and Financial Statements for the three and nine months (Q3 2025) ended September 30, 2025, for full details to the information referenced throughout this presentation.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Cautionary Notes 3 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 1995 (collectively, “forward-looking statements”). These forward-looking statements are made as of the date of this document and the Company does not intend, and does not assume any obligation, to update these forward-looking statements, except as required under applicable securities legislation. Forward-looking statements relate to future events or future performance and reflect the Company's expectations or beliefs regarding future events. The Company's Sustainable Development Strategy goals and strategies are based on a number of assumptions, including, but not limited to, the reliability of data sources; the biodiversity and climate-change consequences; availability and effectiveness of technologies needed to achieve the Company's sustainability goals and priorities; availability of land or other opportunities for conservation, rehabilitation or capacity building on commercially reasonable terms and the Company's ability to obtain any required external approvals or consensus for such opportunities; the availability of clean energy sources and zero-emissions alternatives for transportation on reasonable terms; availability of resources to achieve the goals in a timely manner, adjustments to the goals based on factors including but not limited to growth and data restatements, the Company's ability to successfully implement new technology; and the performance of new technologies in accordance with the Company's expectations. Forward-looking statements include, but are not limited to, statements with respect to the estimation of Mineral Resources and Mineral Reserves, the results of the Optimized Mantoverde Development Project ("MV Optimized FS") and Mantoverde Phase II study, the timing and results of PV District Growth Study (as defined below), the timing and results of Mantos Blancos Phase II Feasibility Study, the timing and success of the Mantoverde - Santo Domingo Cobalt Feasibility Study, the results of the Santo Domingo FS Update and success of incorporating synergies previously identified in the Mantoverde - Santo Domingo District Integration Plan, the timing and results of exploration and potential opportunities at Sierra Norte, the timeline for financial investment decision on Santo Domingo, the completion of the Orion Transaction, the realization of Mineral Reserve estimates, the timing and amount of estimated future production, the costs of production and capital expenditures and reclamation, the timing and costs of the Minto obligations and other obligations related to the closure of the Minto Mine, the budgets for exploration at Cozamin, Santo Domingo, Pinto Valley, Mantos Blancos, Mantoverde, and other exploration projects, the timing and success of the Copper Cities project, the success of the Company's mining operations, the continuing success of mineral exploration, the estimations for potential quantities and grade of inferred resources and exploration targets, the Company's ability to fund future exploration activities, the Company's ability to finance the Santo Domingo development project, environmental and geotechnical risks, unanticipated reclamation expenses and title disputes, the success of the synergies and catalysts related to prior transactions, in particular but not limited to, the potential synergies with Mantoverde and Santo Domingo, the anticipated future production, costs of production, including the cost of sulphuric acid and oil and other fuel, capital expenditures and reclamation of Company’s operations and development projects, the Company's estimates of available liquidity, and the risks included in the Company's continuous disclosure filings on SEDAR+ at www.sedarplus.ca. The impact of global events such as pandemics, geopolitical conflict, or other events, to Capstone Copper is dependent on a number of factors outside of the Company's control and knowledge, including the effectiveness of the measures taken by public health and governmental authorities to combat the spread of diseases, global economic uncertainties and outlook due to widespread diseases or geopolitical events or conflicts, supply chain delays resulting in lack of availability of supplies, goods and equipment, and evolving restrictions relating to mining activities and to travel in certain jurisdictions in which we operate. In certain cases, forward-looking statements can be identified by the use of words such as “anticipates”, “approximately”, “believes”, “budget”, “estimates”, “expects”, “forecasts”, “guidance”, “intends”, “plans”, “scheduled”, “target”, or variations of such words and phrases, or statements that certain actions, events or results “be achieved”, “could”, “may”, “might”, “occur”, “should”, “will be taken” or “would” or the negative of these terms or comparable terminology. In certain cases, forward-looking statements can be identified by the use of words such as “anticipates”, “approximately”, “believes”, “budget”, “estimates”, expects”, “forecasts”, “guidance”, intends”, “plans”, “scheduled”, “target”, or variations of such words and phrases, or statements that certain actions, events or results “be achieved”, “could”, “may”, “might”, “occur”, “should”, “will be taken” or “would” or the negative of these terms or comparable terminology. In this document certain forward-looking statements are identified by words including “anticipated”, “expected”, “guidance” and “plan”. By their very nature, forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause the Company's actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include, amongst others, risks related to inherent hazards associated with mining operations and closure of mining projects, future prices of copper and other metals, compliance with financial covenants, inflation, surety bonding, the Company's ability to raise capital, counterparty defaults, including with respect to Orion, use of financial derivative instruments, foreign currency exchange rate fluctuations, counterparty risks associated with sales of the Company's metals, market access restrictions or tariffs, changes in U.S. laws and policies regulating international trade including but not limited to changes to or implementation of tariffs, trade restrictions, or responsive measures of foreign and domestic governments, changes to cost and availability of goods and raw materials, along with supply, logistics and transportation constraints, changes in general economic conditions including market volatility due to uncertain trade policies and tariffs, availability and quality of water and power resources, accuracy of Mineral Resource and Mineral Reserve estimates, operating in foreign jurisdictions with risk of changes to governmental regulation, compliance with governmental regulations and stock exchange rules, compliance with environmental laws and regulations, reliance on approvals, licences and permits from governmental authorities and potential legal challenges to permit applications, contractual risks including but not limited to, the Company's ability to meet the requirements under the Cozamin Silver Stream Agreement with Wheaton Precious Metals Corp. ("Wheaton"), the Company's ability to meet certain closing conditions under the Santo Domingo Gold Stream Agreement with Wheaton, acting as Indemnitor for Minto Metals Corp.’s surety bond obligations, impact of climate change and changes to climatic conditions at the Company's operations and projects, changes in regulatory requirements and policy related to climate change and greenhouse gas ("GHG") emissions, land reclamation and mine closure obligations, introduction or increase in carbon or other "green" taxes, aboriginal title claims and rights to consultation and accommodation, risks relating to widespread epidemics or pandemic outbreaks; the impact of communicable disease outbreaks on the Company's workforce, risks related to construction activities at the Company's operations and development projects, suppliers and other essential resources and what effect those impacts, if they occur, would have on the Company's business, including the Company's ability to access goods and supplies, the ability to transport the Company's products and impacts on employee productivity, the risks in connection with the operations, cash flow and results of Capstone Copper relating to the unknown duration and impact of the epidemics or pandemics, impacts of inflation, geopolitical events and the effects of global supply chain disruptions, uncertainties and risks related to the potential development of the Santo Domingo development project, risks related to the Mantoverde Development Project ("MVDP"), increased operating and capital costs, increased cost of reclamation, challenges to title to the Company's mineral properties, increased taxes in jurisdictions the Company operates or is subject to tax, changes in tax regimes we are subject to and any changes in law or interpretation of law may be difficult to react to in an efficient manner, maintaining ongoing social licence to operate, seismicity and its effects on the Company's operations and communities in which we operate, dependence on key management personnel, Toronto Stock Exchange ("TSX") and Australian Securities Exchange ("ASX") listing compliance requirements, potential conflicts of interest involving the Company's directors and officers, corruption and bribery, limitations inherent in the Company's insurance coverage, labour relations, increasing input costs such as those related to sulphuric acid, electricity, fuel and supplies, increasing inflation rates, competition in the mining industry including but not limited to competition for skilled labour, risks associated with joint venture partners and non-controlling shareholders or associates, the Company's ability to integrate new acquisitions and new technology into the Company's operations, cybersecurity threats, legal proceedings, the volatility of the price of the common shares, the uncertainty of maintaining a liquid trading market for the common shares, risks related to dilution to existing shareholders if stock options or other convertible securities are exercised, the history of Capstone Copper with respect to not paying dividends and anticipation of not paying dividends in the foreseeable future and sales of common shares by existing shareholders can reduce trading prices, and other risks of the mining industry as well as those factors detailed from time to time in the Company’s interim and annual financial statements and MD&A of those statements and Annual Information Form, all of which are filed and available for review under the Company’s profile on SEDAR+ at www.sedarplus.ca. Although the Company has attempted to identify important factors that could cause the Company's actual results, performance or achievements to differ materially from those described in the Company's forward-looking statements, there may be other factors that cause the Company's results, performance or achievements not to be as anticipated, estimated or intended. There can be no assurance that the Company's forward-looking statements will prove to be accurate, as the Company's actual results, performance or achievements could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on the Company's forward-looking statements.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Overview 4 Mantoverde aerial site view
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 5 Copper in Top-Tier Jurisdictions in the Americas CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Near-term copper growth with a pathway towards ~400ktpa and declining unit costs +50% Cu 29 Copper Strong foundation of 5 assets with long lives, in stable jurisdictions in the Americas 5 Experienced management team focused on responsible production and creating a positive impact on communities Balance sheet strength and financial flexibility to fund the next stage of growth >$1B *Adjusted EBITDA and Available Liquidity are Non-GAAP and Other Performance Measures; shown on a consolidated basis (100% of Mantoverde) unless noted as attributable. 1 As at September 30, 2025, see slide 9. liquidity*,1
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC District-Scale Growth in the Americas 6 Production Open Pit 15+ year mine life 60,000tpd mill capacity +11ktpa cathode capacity3 2025E 51-58 kt Cu MANTOS BLANCOS (100%) Production Open Pit 25+ year mine life 32,000tpd mill capacity4 +60ktpa cathode capacity3 Potential District-Scale Synergies PINTO VALLEY (100%) Cu Mo Ag Production Underground 6+ year mine life 4,400tpd mill capacity COZAMIN (100%) 2025E 23-26 kt Cu Cu Zn Ag Pb Production Open Pit 14+ year mine life 20,000tpd mill capacity +60ktpa cathode capacity3 2025E 49-59 kt Cu 2025E 97-112 kt Cu Fully-permitted, shovel ready Open Pit 19+ year mine life 72,000tpd mill capacity planned SANTO DOMINGO (75%) 1 First 7 years 106 ktpa Cu MV-O run-rate2 125-135 kt Cu HQ, Vancouver, Canada Producing Asset Development Stage Asset Cu Ag Cu Au Fe Co Cu Fe CoAu 1 Mantoverde and Santo Domingo production numbers shown on a 100% basis. Capstone’s ownership interest in Santo Domingo will decrease from 100% to 75% upon closing of SD -Orion transaction. 2 Reflects the first 7-years of production in most recently disclosed NI 43- 101 Technical Report. 3 Excess capacity exists at SX-EW plants at Pinto Valley, Mantos Blancos, and Mantoverde. 4 Mantoverde Optimized brownfield expansion underway to debottleneck the plant to 45,000 tpd mill capacity. 5 2025E production guidance, please refer to the Company’s MD&A for the year ended December 31, 2024. MANTOVERDE (70%)1 Production by Asset5 Pinto Valley 23% Production by Region5 Significant district-scale opportunities surrounding Pinto Valley U.S. 23% Chile 67% Mexico 10% Mantoverde 44% Mantos Blancos 23% Pinto Valley 23% Cozamin 10%
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC A Clear Path to Transformational Growth 7 $0.00 $0.75 $1.50 $2.25 $3.00 $3.75 0 100 200 300 400 500 2024 MV-O Run-Rate Production Future Growth C1 Cash Cost2 (US$/lb) Annual Copper Production (kt) ~280kt SANTO DOMINGO1 ~400kt 184kt MANTOVERDE1 MANTOS BLANCOS COZAMIN PINTO VALLEY Solid Foundation Near-term Growth Future Growth • Santo Domingo project Further Upside with Expansions Across the Portfolio Including MB Phase II, MV-SD Cobalt, and MV Phase II 1 Mantoverde and Santo Domingo production numbers shown on a 100% basis. MV-O and Santo Domingo run-rate Production is based on first seven years average in most recently disclosed NI 43-101 Technical Reports. 2 This is a Non-GAAP and Other Performance Measure; refer to the Company’s news release dated October 30, 2025. C1 cash costs (US$ per payable lb Cu produced). 1 • MV Optimized MV OPTIMIZED1
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Financial 8 Desalination plant located on the coast ~40km west of Mantoverde
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Consolidated Attributable Cash & Short-term Investments $310 $252 Long-term Debt2 $1,036 $875 Net Debt $726 $623 Net Debt / TTM EBITDA 0.9x 0.9x $310M $761M Balance Sheet Strength & Financial Flexibility With Disciplined Approach to Future Growth 9 *Available Liquidity and adjusted EBITDA is a Non-GAAP and Other Performance Measures; shown on a consolidated basis (100% of Mantoverde) unless noted as attributable. 1 As at September 30, 2025. 2 Includes $51.9 million drawn on the cost overrun facility (defined as “Due to related party” as per our financial results) and excludes deferred financing costs and PPA fair value adjustments. 3 Based on 9-month actuals and lower/upper half of production/cost guidance for 2025E EBITDA. Key input assumptions include: CLP/USD: 900:1; MXN/USD: 19:1; Silver: $40/oz; Gold: $3,500/oz; Molybdenum: $18/lb 4 Based on upper/lower end of 2025 production/cost guidance. Santo Domingo project not currently sanctioned. Potential timeline subject to project sanctioning decisions. MV-O and Santo Domingo run-rates based on first full 2-years of production and are on a consolidated basis at 100%. Assumes P65 Fe (CFR China) of $110/t and a long-term $1,800/oz gold price. Net Debt1 (US$M) Available Liquidity*,1 (US$M) $1,071M Cash & ST Investments Undrawn RCF Capacity ~$0 ~$500 ~$1,000 ~$1,500 ~$2,000 ~$2,500 ~$3,000 $4.25/lb Cu $4.75/lb Cu $5.25/lb Cu 2025E EBITDA Annual EBITDA with MV-O Run-rate Production Annual EBITDA with MV-O + Santo Domingo Run-rate Adjusted EBITDA2 Sensitivity (US$M) 3 3, 4 3, 4 1.8x 1.5x 1.3x 1.0x 0.9x Q3/24 Q4/24 Q1/25 Q2/25 Q3/25 Net Debt / TTM EBITDA*
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Capstone Balance Sheet Summary (as at September 30, 2025) 10 Balance Sheet Strength & Financial Flexibility With Disciplined Approach to Future Growth 1 Shown on a consolidated basis (Mantoverde at 100%), except where noted as attributable (Mantoverde at 70% ownership) 2 Weighted average based on published rate at September 30, 2025 3 Amortizing starting September 30, 2024 4 Includes $0.8M of short-term investments 5 These are Alternative Performance Measures. Please refer to the Company’s MD&A for the period ended September 30, 2025 for more information 6 The variable rate on the RCF is 1M term SOFR, 3M term SOFR or 6M SOFR plus 10bps 7 The variable rate is daily SOFR, compounded to a quarterly interest rate, plus 26.161bps 8 The Term Loan is guaranteed by Mitsubishi Materials Corp. (“MMC”), our 30% joint venture partner at Mantoverde, and is not attributable to Capstone Copper. US$M1 Total Facility Size Interest Tenor As at 30-Sep-25 As at 30-Sep-25 Attributable Available Liquidity5 At 30-Sep-25 Revolving Credit Facility Capstone Corporate $1,000M 1M SOFR6 + 1.75%-2.75% May 2029 $239M $239M $761M Senior Unsecured Notes Capstone Corporate $600M 6.75% March 2033 $600M $600M – Mantoverde Term Loan Mantoverde Asset Level $145M 3M SOFR + 2.95% June 20328 $145M –8 – Mantoverde Cost Over-run Facility Mantoverde Asset Level $60M Adjusted SOFR7 + 1.70% 20333 $52M $36M – Total Available / Drawn Debt $1,805M 6.63%2 $1,036M $875M $761M Cash & Cash Equivalents4 $310M $252M $310M Net Debt5 $726M $623M Net Debt / TTM EBITDA 0.9x 0.9x Total Liquidity1 $1,071M Scheduled Debt Repayments (US$M) (as at September 30, 2025) 7 17 28 267 28 28 55 607 0 100 200 300 400 500 600 2026 2027 2028 2029 2030 2031 2032 2033 Revolving Credit Facility Senior Unsecured Notes Mantoverde Term Loan Mantoverde COF Outstanding maturities are long-dated (8)
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 1 3 2 4 LONG-TERM SHAREHOLDER VALUE CREATION Cash Flow From Operations Cost control, productivity and reliability Pursuit of operational excellence and innovation Balance Sheet Strength Targeting <1.0 x net leverage and strong liquidity at conservative Cu price assumptions ahead of sanctioning major capital projects Internal Competition For Capital High Return on Incremental Invested Capital (ROIIC) projects Risk / Reward trade-off studies Macro-Economic Backdrop Copper price outlook Inflationary pressures Counter cyclical investing Disciplined Capital Allocation Through Next Stage of Growth 11
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Operations 12 Mantoverde Copper Concentrator – Flotation Circuit
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Mantoverde 13 Asset Overview Location Atacama Region, Chile; ~900m above sea level Ownership Capstone (70%); Mitsubishi Materials Corp. (30%) Mine Type Open Pit (operating since 1995) Commodity Cu (primary); Au/Fe/Co (secondary) Product(s) LME Grade A copper cathode High quality copper in concentrate with significant gold by-product Capacity 32,000 tpd sulphide concentrator Underutilized 60,000 tpa SX-EW facility 2022 – Commenced construction 2023 – Completed construction for $870M, within 5% of budget 2024 – First saleable copper concentrate in June, 2.5 years post construction start-up 2025 - Achieved nameplate throughput rates in 4th quarter of operation, versus industry average of 13th quarter Mantoverde Development Project Key Achievements For a virtual tour of MVDP, please visit: https://vrify.com/decks/12698-mantoverde-development-project 18 11 26 21 26 27 33 25 34 30 32 35 32 30 20 Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept 2024/2025 Plant Throughput2 (ktpd) 15-day shutdown for facility practical completion Planned maintenance and Chile power outage Ball mill motor failure and planned maintenance Design throughput: 32 ktpd1 1 Per latest Mantoverde Technical Report, recovery range based on first 10 years of mine plan. 2 Throughput figures displayed are the average ore tonnes per day through the sulphide mill for each respective month. 53 76 74 67 71 85 81 85 82 74 73 85 81 90 86 Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept 2024/2025 Recoveries (%) Mining through transition zone Design recovery: 87 - 91%1
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Mantos Blancos 14 Asset Overview Location Antofagasta Region, Chile; ~900m above sea level Ownership Capstone (100%) Mine Type Open Pit (operating since 1960) Commodity Cu (primary); Ag (secondary) Product(s) Sulphide concentrate + LME Grade A copper cathode Capacity 20,000tpd sulphide concentrator, underutilized 60,000tpa SX-EW facility Growth Catalysts • Phase II brownfield expansion study expected in 2026 • Analyzing increase in sulphide concentrator throughput capacity from 20 ktpd to around 27 ktpd using existing/underutilized equipment • Evaluating potential for increased cathode production via an opportunity to re-leach spent ore from historical VAT leaching operations • Exploration Potential • Mineralization open at depth and adjacent to pits • Several high potential opportunities for in-mine and brownfield exploration targets identified 1 Throughput figures displayed are the average ore tonnes per day through the sulphide mill for each respective month. 2 Per latest Mantos Blancos Technical Report. 2024 & 2025 Throughput1 Performance (ktpd) Confidence in Achieving Throughput Design Rates Successful debottlenecking project and implementation of our Asset Management Framework have reduced variability in the milling process and led to a significant increase in overall throughput 14.2 16.2 14.1 19.6 19.1 21.3 18.1 Q1/24 Q2/24 Q3/24 Q4/24 Q1/25 Q2/25 Q3/25 Design throughput: 20 ktpd2 Debottlenecking project tie-in completed Planned maintenance and Chile power outage in Feb. Planned and unplanned maintenance
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Pinto Valley 15 Asset Overview Location Arizona (Globe-Miami), USA; ~1,000m above sea level Ownership Capstone (100%) Mine Type Open Pit (operating since 1975) Commodity Cu (primary), Mo (secondary) Product(s) Sulphide concentrate + Grade A copper cathode Capacity 60,000 tpd sulphide concentrator + 11,000 tpa SX-EW facility Growth Catalysts • District growth study evaluating inclusion of a portion of the 1B tonnes of mineral resources into the mine plan • Expansion and mine-life extension through 2050 • Evaluating near-mine district consolidation opportunities, specifically Copper Cities, in one of the most prolific mining jurisdictions Pinto Valley (Arizona, USA) Pinto Valley District in Globe-Miami, Arizona
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Cozamin 16 Asset Overview Location Zacatecas, Mexico; ~2,400m above sea level Ownership Capstone (100%) Mine Type Underground (operating since 2007) Commodity Cu (primary); Ag (secondary) Product(s) Sulphide concentrate Capacity 4,400 tpd sulphide concentrator Growth Catalysts • Mine plan enables higher mining productivity, dilution control, and overall higher resource extraction • Mine-life extended by ~6 years through 2030: • Exploration on drill targets open to the southeast, northwest, and down- dip • Implementation of selective mining techniques to decrease dilution and lower mining costs • Enhanced pillar recovery, leveraging the benefits of the new paste backfill plant Dry Stack Tailings and Paste Backfill Plant • The new approach, which is considered industry best practice, involves filtering tailings to extract more water, which can be reused. • Some of the filtered tailings are used to produce paste which is placed underground as mine backfill. The rest are placed in a dry stack, which is more stable than a conventional tailings storage method.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Growth & Exploration 17 Santo Domingo, Chile
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC MANTOS BLANCOSPINTO VALLEY MANTOVERDE District Growth Study • Mill throughput expansion and optimization • Expansion of the use of leach technology including pyrite agglomeration Mine Life Extension • Mine life extension potential through exploration • Refinement of cut and fill to reduce mining dilution • Drift and fill methods to increase pillar recovery MV Optimized • Expansion from 32 to 45ktpd throughput • $176M initial capex with an incremental 20kt Cu pa Pyrite Augmentation & Cobalt • Opportunity to reduce sulphuric acid consumption and produce by-product cobalt MV Phase II • Potential for expansion from 45 to ~90ktpd • Significant exploration potential Phase II Study • Low capex expansion opportunity from 20ktpd to ~27ktpd using idled mill capacity • Evaluating potential for additional cathode production via re- leaching of spent ore Santo Domingo FS • Base case Cu/Fe/Au project Other • Sierra Norte Cu sulphides integration • SD/SN Cu oxides integration • District cobalt production SANTO DOMINGOCOZAMIN Expansion & Optionality Across the Portfolio MV-SD 35km Apart Mine Life Extension and Expansion Opportunities Across our Producing Assets Fully Permitted Project; Key to Unlock MV-SD District Synergies 18
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 19 Expansion & Optionality Across the Portfolio Project Status MV Optimized +20kt copper/year incremental production1 Low capital intensity, brownfield expansion Construction underway Santo Domingo +120kt copper/year incremental production2 Builds on jurisdictional advantage, one step in unlocking MV-SD district potential Fully permitted, sanctioning decision expected H2 2026 MV Pyrite Augmentation & Cobalt Reduction in sulphuric acid requirements and by-product cobalt production Work ongoing with pilot plant testing underway Mantos Blancos Phase II Low capital intensity, utilizes existing excess sulphide mill and SX-EW capacity Study work ongoing Santo Domingo Oxides & Cobalt Incremental to SD base case FS leveraging underutilized district infrastructure Resource conversion drilling Sierra Norte Integration Opportunity for increased sulphide Cu production at SD and oxide Cu cathodes at MV Resource definition drilling Mantoverde Phase II Potential incorporation of existing resource base into mine plan Exploration underway PV District Consolidation Opportunity to unlock district-scale potential and synergies Scoping engineering 1 Mantoverde (MV) Optimized is based on the life of mine average incremental production per the 2024 Feasibility Study released on October 1, 2024. 2 Santo Domingo (SD) is based on the average of the first full 5 years of copper production in 2024 Feasibility Study released July 31, 2024. 3 Medium to long-term projects are speculative in nature and are not based on published NI 43-101 Technical Reports. Near-TermMedium-Term3Long-Term3
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 20 Note: All currency values shown in U.S. dollars unless otherwise stated; Refer to the Mantoverde Optimized Feasibility Study press release (October 1, 2024) and the Mantoverde Development Project Feasibility Study press release (January 5, 2022). Mantoverde operational and financial information shown on a 100%-basis. 1 Reflects the first 10-years of production. Mine Life (Years) 19 25 MVDP MV-O Mill Throughput (ktpd) Avg. Annual Gold Production 32 45 MVDP MV-O First 10 Years (kozpa) ~30 ~36 MVDP MV-O Avg. Annual EBITDA (US$M) First 10 Years ~500 ~600 MVDP MV-O Avg. Annual Copper Production ~102 ~123 MVDP MV-O First 10 Years (ktpa) Mill Feed (Mt) & Head Grade (%) 236Mt 394Mt MVDP MV-O 0.60% 0.49% MV-O (2024) vs. MVDP (2021) Feasibility Study +6 years Incremental Mine Life Incremental Avg. Annual Copper Production1 +20ktpa Incremental Avg. Annual EBITDA1 +$100M/yr Mantoverde-Optimized Key Metrics at a Glance Cu 29 Copper
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Mantoverde Optimized A Capital-Efficient Brownfield Expansion 21 2024 2025 2026 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Feasibility Study Approval of Long-Lead Items DIA Permit Detailed Engineering Sanctioning Construction Ramp Up Expansionary Capital Cost Estimate (by area) As at Sanctioning ($ millions) Mine 43 Concentrator processing plant 107 Oxide leach optimization 19 Desalination plant 7 TOTAL EXPANSIONARY CAPITAL COST 176 2025 vs 2026 Portion of Spend ~15% / 85% Note: All currency values shown in U.S. dollars unless otherwise stated; Refer to the Mantoverde Optimized Feasibility Study press release (October 1, 2024) and the Mantoverde Development Project Feasibility Study press release (January 5, 2022), as well as the Mantoverde Optimized Sanctioning press release (August 8, 2025). Mantoverde operational and financial information shown on a 100%-basis. 1 Based on $4.10/lb Cu price and $1,800/oz Au price 2 Reflects the first 10-years of production. $176M Initial Capex for Brownfield Expansion Opportunity Incremental Avg. Annual Copper Production2 +20ktpa Capital intensity/tonne of incremental annual Cu equivalent production1 $9,000/t
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Santo Domingo 22 Asset Overview Location Atacama Region, Chile; low elevation at ~1,000m above sea level Ownership Capstone (75%), Orion Resource Partners (25%) Mine Type Open Pit (+19 year mine life) Commodity Cu/Fe (primary); Au/Co (secondary) Deposit Iron oxide-copper-gold (IOCG) type deposit Permitting Fully-permitted (DL-600: valid 15 years post commercial production) • Experienced project team with mine build experience in the Atacama • Located 35km away from Mantoverde, where Capstone recently completed the Mantoverde Development project for $870M (within 5% of original budget) • Unlocks Mantoverde-Santo Domingo district optimization opportunities • Updated Feasibility Study results released in July 2024 • Optimized mine plan, updated capital and operating cost estimates, and incorporated all experience gained throughout engineering and construction of nearby Mantoverde Development Project • Advancing opportunities to incorporate the recently acquired Sierra Norte project and Santo Domingo’s copper oxide material into the mine plan Proven Builders + Operators in the Region For a virtual tour of Santo Domingo and the MV-SD District: https://youtu.be/n-FyVJ9t2JE?si=UD2U92Aomvy4FIyV 1 Capstone’s ownership interest in Santo Domingo will decrease from 100% to 75% upon closing of SD -Orion transaction. 1
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Santo Domingo Key Metrics at a Glance - July 2024 Feasibility Study Cu 29 Copper 23 Post-tax IRR 24% Initial Capex; 3 Year Post-tax Payback $2.3Bn Avg. Annual EBITDA2 ~$850M Mine Life Avg. Annual Cu Production2, plus ~3.7Mt of High-grade Iron Ore Production2 19 Year 106kt C1 Cash Costs2 (by-product basis), $1.27/lb C1 Cash Costs2 (co-product basis) $0.28/lb In-Country Taxes Paid (LOM); Expected to Generate +1,000 Jobs +$2Bn Note: Refer to the Santo Domingo Feasibility Study press release announced on July 31, 2024. Santo Domingo operational and financial information shown on a 100%-basis. 1 Based on $4.10/lb Cu and $110/t P65 CFR China Fe in the base case and 10% higher prices in the $2.1Bn NPV(8%) case. 2 Reflects the first 7-years of production. Post-tax NPV(8%) at $4.10/lb LT Cu; $2.1Bn NPV(8%) at +10% Cu Prices1 $1.7Bn
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Santo Domingo Flowsheet Long Mine Life with a Robust Production Profile 24 Primary Crusher Aerial view of Santo Domingo site with proposed locations of key infrastructure Proposed process plant infrastructure (beginning on the right at the primary crusher and moving left) 0 20 40 60 80 100 120 140 160 180 200 Yr. 1 Yr. 2 Yr. 3 Yr. 4 Yr. 5 Yr. 6 Yr. 7 Yr. 8 Yr. 9 Yr. 10 Yr. 11 Yr. 12 Yr. 13 Yr. 14 Yr. 15 Yr. 16 Yr. 17 Yr. 18 Yr. 19 CuEq. Production (kt) Copper (kt) Iron Ore (kt) ~74% ~26% Commodity Mix: First 7 Years1 Commodity Mix: LOM1 Average Cu Production: 106kt Average C1 Cash Costs: $0.28/lb Average Cu Production: ~68kt Average C1 Cash Costs: $0.33/lb ~66% ~34% Note: Renderings provided by Ausenco. Refer to the Santo Domingo Feasibility Study press release announced on July 31st, 2024. Santo Domingo operational and financial information shown on a 100%-basis. 1 Reflects copper and iron ore revenue only; Long-term commodity price assumptions include: $4.10/lb Cu; $85/t 62% CFR China; and $110/t 65% CFR China. Evaluating additional copper production optionality via Santo Domingo oxides and integration of Sierra Norte property
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC $33 $23 $23 $12 $34 $23 $23 $22 $9 QB2 (2024) Quellaveco (2022) Cobre Panama (2019) Mantoverde (2024) Bagdad Exp. (2023) Centinela Exp. (2023) El Abra Exp. (2024) Santo Domingo (2024) MV Optimized Exp. (2025) Santo Domingo - Competitive Capital Intensity With Few Recent Large Scale Cu Feasibility Studies 25 Note: Refer to the Santo Domingo Feasibility Study press release announced on July 31, 2024. Santo Domingo operational and financial information shown on a 100%-basis. Source: Company filings, Wood Mackenzie 1 Calculated as initial capital cost divided by LOM CuEq. Production Area Cost (US$M) % of Total Mine $370 16% Process Plant $486 21% Tailings and Water Reclaim $67 3% Plant Infrastructure $144 6% Port & Port Infrastructure $283 12% External Infrastructure $151 7% Total Direct Cost $1,500 65% Indirect Costs $414 18% Owner Costs $109 5% Contingency $291 13% Total Indirect Costs $814 35% Total Initial Capital $2,315 100% Initial Capital Cost – Santo Domingo Capital Intensity Benchmarking (US$’000/t)1 Recently Built Select Projects Less than 1,500 meters above sea level ~4,000 Elevation (meters above sea level) ~3,500 ~900 ~1,250 ~1,000~200 ~3,800~2,300 ~900
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 26 Unlocking the Value of the Santo Domingo Project Next Phase of a Long-Standing Partnership with Orion up to $360M total investment1 1 Please see Company’s press release from October 13, 2025 for details regarding the total strategic investment amount. 2 Final Investment Decision. Unlocks a New World-Class Copper Mining District in Chile Builds on a Long-Standing Partnership with Orion, a Premier Global Mining Partner Realizes Significant Value and De-Risks Capstone’s Project Funding Requirements Retains Future Optionality to Re-Consolidate Full Ownership Through a Buy-Back Option Santo Domingo 75% Recognizing the Value of Santo Domingo Creating a Partnership Built to Succeed 25% $225M cash contribution at FID2 $75M matching cash contribution Up to $60M contingent cash consideration unique buyback option to re-consolidate 100% ownership
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Completed: Permitting 2023 and Prior 2024 Completed: Study Obtained required permits for the project Published updated Feasibility Study for the Santo Domingo, highlighting a 24% post-tax IRR Completed: Joint Venture Partner 25% minority interest sale to Orion, representing next phase of a long- standing partnership In Progress: Balance Sheet Obtain optimal project finance facility in collaboration with JV Partner for ~$1.2Bn1 over next 9-12 months In Progress: Financing Targeting <1.0x net debt to EBITDA3 leverage and >$500M in liquidity4 prior to project sanctioning Expected Sanctioning Decision 2025 Ongoing Through to H2 2026 In Progress: Engineering & Optimization Progress detailed engineering; pursue incremental copper production optionality and infrastructure optimization opportunities Macro Markets Monitoring of global markets and broader economic conditions, copper price outlook, inflation and supply chains 27 2 Santo Domingo Path Forward Advancing Remaining Workstreams in Parallel 1 Based on debt service coverage and debt to equity ratios, several independent banks have provided an indicative project finance range of $1.1-1.3Bn plus a $100M cost over-run facility (not reflected in the numbers above). 2 Reflects target balance sheet performance measures before proceeding with a sanctioning decision for Santo Domingo. 3 Net debt to EBITDA leverage is a non-GAAP Alternative Performance Measure. Please refer to Cautionary Note Non-GAAP and Alternative Performance Measures on page 2. 4 Available liquidity is a non-GAAP Alternative Performance Measure. Please refer to Cautionary Note Non-GAAP and Alternative Performance Measures on page 2.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Remaining Funding Requirement 28 Santo Domingo Illustrative Funding Structure Prudent Approach to Capital Allocation in Pursuit of Transformational Growth Note: Refer to the Santo Domingo Feasibility Study press release announced on July 31, 2024. 1 The estimated $2.3B capital figure includes $291M of contingency and is based on a long-term copper price of $4.10/lb. 2 Based on debt service coverage and debt to equity ratios, several independent banks have provided an indicative project finance range of $1.1-1.3Bn plus a $100M cost over-run facility (not reflected in the numbers above). 3 Based on Orion upfront cash contribution of $225M and initial matching capital contribution of $75M. 4 Please see the MD&A for the three and nine month period ended September 30, 2025. 5 As at September 30, 2025. Available Liquidity and adjusted EBITDA is a Non-GAAP and Other Performance Measures; shown on a consolidated basis (100% of Mantoverde) unless noted as attributable. 6 Assuming initial capital per Santo Domingo 2024 Feasibility Study; inclusive of $260 million in gold stream proceeds and giving effect to approximately $1.2 billion in project level financing and Orion’s contributions and distributions. Implies drawdown of $225 million payment to Capstone and $75 million Orion contribution following FID, contingent payments not included. Assumes Capstone uses proceeds from sale of 25% to fund cash calls. $260M $1.2Bn2$2.3Bn1 Initial Capex Less: WPM Au Stream Proceeds Less: Illustrative Project Financing Net Funding Requirement Remaining Funding Requirement Less: Orion Contribution ~$0.8Bn 75% $300M3 ~$0.5Bn 25% Consolidated Net Debt5 of $726M 0.9x Net Debt / LTM EBITDA Liquidity5 of $1.1Bn Capstone Q3 2025 Balance Sheet Summary4 $225M cash contribution at FID and $75M within 6 months of FID Contingent consideration up to $60M for upside opportunities Equity subscription of $10M in Capstone Levered project IRR to Capstone >75% 6 Transaction Impact Capstone / Orion to jointly fund Santo Domingo (75% / 25%) post Orion Contribution Remaining Project Funding Capstone portion of remaining funding requirement expected to be funded through internally generated cash flow
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC MB Phase II Study 29 Opportunity Highlights Stage / Impact Continuous Improvements • Controlled Potential Sulphidation (CPS) • Flotation activator for copper oxides in sulphide circuit • Energy Efficient Pulp Lifter (EEPL) Conversion • Improving ball mill energy efficiency • At 20ktpd throughput, opportunity to expand sulphide Cu production by ~5ktpa Phase II • Brownfield expansion with plan to increase mill throughput from 7.3Mtpa (20ktpd) to ~10Mtpa (~27ktpd) • Capital required for additional equipment in the following areas: concentrate filtration, thickening and filtering of tailings • Phase II study expected in 2026 • Targeting an additional ~10ktpa of Cu over the first 10-years Tailings Reprocessing • Opportunity to re-leach ripios from historical VAT leaching operations and coarse/fine tailings • ~120Mt at ~0.30% CuT • Strong recoveries shown from column test results • Underutilized SX-EW capacity (60ktpa Cu cathode) • Capital required to install dynamic leach pad, agglomeration and stacking infrastructure • Opportunity to increase cathode production by ~25ktpa Cu over 15 years (with no mining or crushing costs)
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 30 Enhancing the Pipeline Through Exploration MANTOS BLANCOSPINTO VALLEY MANTOVERDE SANTO DOMINGO + SIERRA NORTECOZAMIN District Growth Study • Evaluating near-mine district consolidation opportunities with the potential to support mill throughput expansion and optimization • Significant M&I resources not included in reserves, potential to create economies of scale at the mill Mine Life Extension • Mine life extension potential, and opportunity to improve the consistency of the current production profile, through exploration • Focus on Mala Noche targets and historical vein workings Near-Mine Exploration • Targeting higher Cu grades • Exploring new areas within or beside resource pit, targeting higher grades and mineralization continuity, as well as to the north of the pit with the potential to increase resources District Exploration • Testing targets north of current pit to inform MV Phase II Near-Mine Exploration • Infill drilling and geophysics exploration to add additional sulphide and oxide resources below and lateral to existing resource pit shell District Exploration • Evaluating exploration upside at nearby sulphide & oxide deposits Santo Domingo • Advancing opportunities to incorporate copper oxide material into the mine plan Sierra Norte • Advanced exploration for oxides and sulphides at Sierra Norte • Early-stage exploration on the surrounding areas Mala Noche Vein MNFWZ – Vein 20 MNFWZ DeepMNV West SR Gap Capstone updated total 2025 consolidated exploration expenditure guidance to $40 million (from $25 million previously), focusing on brownfield exploration across the portfolio and greenfield exploration at Mantoverde and Santo Domingo/Sierra Norte
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC MV-SD: Unlocking District Scale Optimization • Targeting +250,000 tonnes per year of low-cost copper production with a significant by-product of premium grade iron ore • Potential to be one of the largest and lowest cost cobalt producers in the world • Santo Domingo Oxides • Sierra Norte Integration • Mantoverde Phase II • Mantoverde Development Project (MVDP) and MV Optimized (MV-O) • Santo Domingo Cu/Fe Project; MV-SD Cobalt • Santo Domingo Port & Desalination Plant Base Case Future Production Profile 1 3 Creating a World-class Mining District Planned Santo Domingo Port MV Desal Plant Mantoverde Santo Domingo Project 31 Sierra Norte • Ports • Desalination Plant • Oxide Plant District Infrastructure Optimization2
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC MV-SD Exploration Program 32 Mantoverde Initial Two-Year $25M Exploration Program • Targeting higher copper grades • Exploring new areas adjacent or inside the current Mantoverde pits • Testing high priority targets in the northern area of Mantoverde land package Estrellita Santo Domingo 10 km N Mantoverde & Santo Domingo District1 Target Stage (1) Victoria, (3) La Reina, (4) Paloma Sur, (5) San Manuel Initial Drill Testing (6) Paloma and (2) Animas Intermediate Drill Testing 1 Red dots represent regional copper occurrences and small copper mines Mantoverde District Exploration • Initial and intermediate drill testing of targets north of Mantoverde (4-8 km from current pit) • Targeting based on 3D structural model, geochemistry, and geophysics • Target size potential between ~200-300Mt; between 0.4%- 0.6% CuT SD & SN Future Exploration • Definition of Oxide resource in Santo Domingo & Estrellita and Sulphides expansion in Santo Domingo. • Advanced exploration for Oxides and Sulphides in Sierra Norte • Early-stage exploration on the Enami ground surrounding Sierra Norte 2 1 6 5 3 4 MV plant Northern Corridor Santa Clara Corridor IP anomalies Sierra Norte Mantoverde For an interactive presentation outlining the progress and results from our exploration program, visit: https://vrify.com/decks/19778
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC MV Exploration Program Results from Phase 1 33 Highlights from Initial Results: • Higher than expected grades in Brecha Flores sector, where drill intercepts returned copper grades above those predicted by the current block model • Results consistent with the current block model at Mantoverde Sur (“MVS”) and Mantoverde Norte (“MVN”), enhancing confidence and supporting the potential upgrade of the resource categorization • Strong results along the Santa Clara Corridor confirming the presence of higher grades than the current block model with the potential for resource growth in between active pits • Results from step-out drilling continue to demonstrate extension of the mineralization to the north of the current Mantoverde pit into the Animas area, confirming continuity along strike • District-scale exploration potential with the completion of a 10-kilometre Induced Polarization (IP) geophysical survey along the northern corridor, which has informed the location of high-priority targets that will be tested in Phase 2 Cross Section of Santa Clara Corridor Overview of Phase 11: 30,000-metres of drilling focused on areas adjacent to MV-O Pit Reserves and priority targets located just north of current operation 1 Refer to the news release dated October 7, 2025 entitled “Capstone Copper Reports Results of Phase 1 Drill Program at Mantoverde.”
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 34 Santo Domingo and Sierra Norte Exploration Program Increased District Exploration Budget Key programs include: – 54,700 metre drill program at Santo Domingo and the adjacent Estrellita deposit to delineate the oxide resource and explore near-mine sulphides – 19,200 metre drill program to advance exploration and resource delineation at the near- by Sierra Norte deposit As a result, Capstone updated total 2025 consolidated exploration expenditure guidance from $25M to $40M IOCG type of mineralization with copper, gold, iron and cobalt ~340Mt of sulphide resource not included into reserves Opportunity to define an oxide resource in the Santo Domingo and Estrellita pits Sulphide exploration potential between Santo Domingo and Iris Norte pits IOCG type of mineralization with copper, gold, iron and cobalt Historic resource estimate of ~100Mt at ~0.45% Cu with exploration upside Opportunity to expand the sulphide resource and define an oxide resource Several geophysical targets poorly tested or untested Santo Domingo Exploration Potential Sierra Norte Exploration Potential Source: Santo Domingo Feasibility Study (2024). Note: Iron Oxide Copper Gold (“IOCG”). 1 See slide 53 for historical Sierra Norte resource estimate. 1
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC ESG 35 Mining at Mantoverde with one of four new electric rope shovels
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Sustainable Development Strategy 36 • Our Sustainable Development Strategy and GHG reduction targets follow a detailed review of our operations to establish a 2021 baseline. • The Strategy identifies five initial priorities with milestones, goals and targets supported by robust reporting and evaluation processes under the direction of the Board of Directors and senior leadership: Visit Responsibility - Capstone Copper to learn more about our Sustainable Development Strategy and initiatives to reach our targets. Climate Water Tailings Biodiversity Communities Interim target: reduce GHG emissions from fuel and power by 30% by 2030 compared to a 2021 baseline year. Reduce freshwater use intensity by 2030, compared to a 2021 baseline. Increase low quality or recycled water as a proportion of total water consumed by 2030, compared to a 2021 baseline. Implement the Global Industry Standard for Tailings Management (GISTM) across all Capstone TSFs by YE 2028. All sites assessed against the Capstone Biodiversity Standard by 2025. Reclamation, reforestation, and habitat conservation project-specific metrics are achieved, with results annually reported. All sites assessed against the Capstone Social Performance Standard by 2025.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC GHG Emissions Reduction Targets 37 Climate Interim target: Reduce GHG emissions from fuel and power by 30% by 2030 compared to 2021 baseline year. Our carbon reduction strategy to 2030: • Transition to 50% renewable electricity in Chile by 2025 • Transition to >90% renewable electricity across Capstone by 2030 • Study renewable power self-generation and storage options at Pinto Valley • Assess future growth opportunities against our 2030 target and incorporate carbon reduction into feasibility studies • Pursue diesel displacement opportunities GHG Emissions Reduction Pathway to 2030. 2021 Baseline Scenario 2 (2025) Scenario 3 (2030) 2030 (Total) - 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 Total GHG Changes (tCO2e, change relative to 2021) 2021 Baseline Scenario 2 (2025) Scenario 3 (2030) 2030 (Total) - 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 GHG Intensity Reduction (tCO2e/ktCu) +8% -36% 30% decrease from 2021 to 2030 -20% -33% 46% intensity reduction from 2021 to 2030 Projected near term increase in absolute emissions while intensity will decrease year over year. 1Scenario 2 includes the change from 100% coal/fossil fuel powered PPA at MB and MV to 50% renewable energy in 2025, as per existing PPAs. Under this scenario, the results show that Capstone’s total GHG will be 8% higher, while GHG intensity will be 15% lower when comparing 2021 and 2030 figures (excluding leach CO2). 2. Scenario 3 assumed 100% of electric power at MB, MV and PV will be sourced from renewable sources. Under this scenario, Capstone’s total GHG and GHG intensity for 2030 will be 31% and 46% lower compared to 2021, respectively (excluding leach CO2). 1 1 22
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Investment Thesis 38
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 39 COPPER IN TOP-TIER JURISDICTIONS IN THE AMERICAS Peer-Leading Copper Production Growth Declining Cash Costs Best-in-Class Mine Build and Operating Team Strong Balance Sheet
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Capstone vs. Key Peers 2024A Production Metrics (kt) Diversified Portfolio of High-Quality Copper Assets • 4 producing assets located in top-tier jurisdictions • Well-balanced portfolio across producing assets • Increased volumes from MVDP sulphide operations already delivering lowest cost production in portfolio • Mantos Blancos mill capacity successfully debottlenecked and delivering nameplate capacity Portfolio Highlights 40 Copper Production by Region (2024) Copper Production by Asset (2024) # of Producing Mines 4 5 5 42 3 1 3 1 Chile 55% Canada 23% Peru 22% Zambia 93% Mauritania 4% Turkey 3% Canada 100% 2 Gibraltar 100% Chile 67% USA 23% Mexico 10% Brazil 100% Caraiba 87% Tucuma 13% Kansanshi 40% Trident- Sentinel 54% Guelb Moghrein 4% Cayeli 3% Candelaria 44% Caserones 34%Chapada 12% Eagle 2% Neves-Corvo 8% Zinkgruvan 1%Antamina 22% Highland Valley Copper 23% Quebrada Blanca 47% Carmen de Andacollo 9% Constancia 72% 1 Reflects Capstone 2025E production guidance and the 54kt production increase from 2024 production of 184kt. For assumptions underlying the 2025E guidance, please refer to the Company’s MD&A for the year ended December 31, 2024. 2 Does not include the 45kt from December 9, 2024 publicly announced sale of European assets (Zinkgruvan and Neves Corvo) to Boliden. 3 Capstone production numbers refer to the mid-point of 2025E guidance found on page 43 of this presentation. MV 44% MB 23% PV 23% Cozamin 10% Peru 72% Canada 28% Lalor 9% Copper Mountain 19% Chile 78%Brazil 12% USA 2% Portugal 8% Sweden 1% Copper Production (2024A) 184 446 431 324 138 48 41 54 45238 369 2 2025 Guidance3 2025 Guidance3
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 0 2,000,000 4,000,000 6,000,000 8,000,000 10,000,000 12,000,000 14,000,000 16,000,000 $0.00 $2.00 $4.00 $6.00 $8.00 $10.00 $12.00 $14.00 $16.00 Oct-24 Nov-24 Dec-24 Jan-25 Feb-25 Mar-25 Apr-25 May-25 Jun-25 Jul-25 Aug-25 Sep-25 Volume (RHS) Price (LHS) Capstone 12-Month Price (C$/share) & Total Volumes3 Capstone Copper – Capital Structure 41 One-Year Average Daily Trading Volume of ~3.4 million shares 1 Shares outstanding as at September 30, 2025. 2 As per ASX announcement dated October 6, 2025. 3 Capstone Copper’s Market Cap based on closing share price on October 29, 2025. 4 Prices and total volumes sourced from FactSet and include all Canadian exchanges, in addition to the ASX. Top Shareholders* % of S/O Management & Board Ownership** ~2% * Insiders including members of the Board of Directors and Senior Leadership who own, directly or indirectly, or exercise control or direction over voting securities of Capstone Copper’s voting rights. Share Metrics Shares Outstanding (FD) 1 762 million Shares Held as ASX CDIs 2 203 million Market Cap 3 US$6.8Bn Analyst Coverage Barrenjoey J.P. Morgan Bradesco BBI Macquarie BMO Capital Markets Moelis & Company Canaccord Genuity Morgans CIBC Capital Markets National Bank Financial Citibank Paradigm Capital Inc. Clarksons Raymond James Cormark Securities Inc. RBC Dominion Securities Inc. Desjardins Scotia Capital Global Mining Research Stifel Goldman Sachs TD Securities Inc. Jefferies
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Appendix 42 Mantoverde Open Pit
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 2025 Guidance Breakdown 43 1 This is an alternative performance measure; refer to the Company’s press release dated January 20, 2025. C1 cash costs (US$ per payable lb Cu produced). 2 Mantoverde and Santo Domingo shown on a 100% basis. Cu Production (kt) C1 Cash Costs1 (US$/lb Cu) Sustaining Capital (US$M) Expansionary Capital (US$M) Capital Stripping (US$M) Total (US$M) Sulphide Business Capital Expenditures Mantoverde2 68 – 80 $1.25 – $1.55 Mantoverde2 $75 $30 $70 $175 Mantos Blancos 43 – 51 $2.20 – $2.50 Mantos Blancos $80 - $110 $190 Pinto Valley 51 – 58 $2.55 – $2.85 Pinto Valley $75 - $50 $125 Cozamin 23 – 26 $1.60 – $1.80 Cozamin $25 - - $25 Total Sulphides 185 – 215 $1.85 – $2.15 Santo Domingo2 - $40 - $40 Consolidated (US$M) $255 $70 $230 $555 Cathode Business Mantoverde2 29 – 32 $4.10 – $4.40 Total Exploration (US$M) $40 Mantos Blancos 6 – 8 $3.40 – $3.70 Total Exploration (US$M) $25 Total Cathodes 35 – 40 $3.95 – $4.25 Total Mantoverde2 97 – 112 $2.10 - $2.36 Total Mantos Blancos 49 – 59 $2.35 - $2.66 Consolidated 220 – 255 $2.20 – $2.50 FY 2025FY 2025
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 2025 Actuals Year-to-Date 44 1 This is an alternative performance measure; refer to the Company’s press release dated October 30, 2025. C1 cash costs (US$ per payable lb Cu produced). 2 Mantoverde shown on a 100% basis. 3 Adjusted net income is attributable to shareholders. Q1 2025 Q2 2025 Q3 2025 Cu Production (tonnes) C1 Cash Costs1 (US$/lb Cu) Cu Production (tonnes) C1 Cash Costs1 (US$/lb Cu) Cu Production (tonnes) C1 Cash Costs1 (US$/lb Cu) Sulphide Business Mantoverde2 16,268 $1.53 16,507 $1.51 15,219 $1.40 Mantos Blancos 12,272 $2.23 13,945 $1.87 13,591 $1.94 Pinto Valley 10,886 $3.84 10,125 $3.89 9,949 $3.63 Cozamin 6,524 $1.28 6,509 $1.49 6,145 $1.51 Total Sulphides 45,950 $2.23 47,086 $2.20 44,904 $2.00 Cathode Business Mantoverde2 6,272 $4.81 8,479 $3.96 8,550 $3.76 Mantos Blancos 1,574 $3.96 1,851 $3.64 1,826 $4.37 Total Cathodes 7,846 $4.64 10,330 $3.90 10,376 $3.87 Total Mantoverde2 22,540 $2.46 24,986 $2.35 23,769 $2.27 Total Mantos Blancos 13,846 $2.43 15,796 $2.09 15,417 $2.24 Consolidated 53,796 $2.59 57,416 $2.45 55,280 $2.42 Revenue (US$M) $533.3 $543.2 $598.4 Adj. EBITDA (US$M) 1 $179.9 $215.6 $249.2 OCF before W/C (US$M) $166.1 $212.4 $231.2 Adj. Net Income1,3 (US$M) $8.1 $27.5 $49.4 Adj. EPS1 (US$/share) $0.01 $0.04 $0.06 $2.20 $2.30 $2.40 $2.50 $2.60 $2.70 $2.80 $2.90 0 10 20 30 40 50 60 70 Q3/24 Q4/24 Q1/25 Q2/25 Q3/25 Quarterly Copper Production (kt) and C1 Cash Costs (US$/lb) 1 Sulphides Cathodes Cash Costs 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 0 50 100 150 200 250 300 Q3/24 Q4/24 Q1/25 Q2/25 Q3/25 Quarterly Adj. EBITDA 1 (US$M) and Adj. EBITDA Margin (%)
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 45 Proven Mine Building and Operating Team In-place +100 Years of Combined Mine Operations, Projects and Senior Leadership Experience Cashel Meagher President & CEO • +30 Years Experience • Former SVP, COO of Hudbay Minerals • Extensive mine building and operating experience, including leading the construction of Constancia James Whittaker SVP & COO • +30 Years Experience • Former President of Escondida • Significant experience leading operations and project development in North and South America Raman Randhawa SVP & CFO • +25 Years Experience • Chartered Professional Accountant (CPA,CA) with capital markets, treasury and financial reporting experience • Prior to joining Capstone in 2018, Raman spent 13 years at Goldcorp in variety of operational finance leadership roles Peter Amelunxen SVP, Technical Services • +25 Years Experience • Former VP, Technical Services at Hudbay Minerals • Deep knowledge of Latin American mining operations
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Board of Directors 46 Patricia Palacios Independent Director Peter Meredith Lead Independent Director Alison Baker Independent Director Anne Giardini Independent Director Cashel Meagher Director, President & CEO John MacKenzie Non-Executive Chair Gordon Bell Independent Director Rick Coleman Independent Director
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Mantos Blancos Exploration Potential Near-mine and District Opportunities 47 Mantos Blancos Exploration Potential Opportunity to add additional sulphide and oxide resources below and lateral to the existing resource pit shell Nora-Quinta • Exploration Target: ~30-40Mt @ 0.5-0.7% CuT; • Potential new mine phase beyond 2036 Barbara SW, Central and SE • Exploration Target: ~80-90Mt @ 0.7-0.8% CuT; • Geophysical exploration and drilling to unlock additional value Veronica Oxides • Exploration Target: 2-4Mt@ 0.25-0.35% CuS • Exploration program underway • Potential oxide LOM extension from 2028 District Sulphide & Oxide Deposits • Capri and Rosario targets Barbara SW Barbara Central Barbara SE 3D view Veronica Barbara SE Barbara SW Barbara Central Nora-Quinta
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Mantos Blancos Exploration Potential (Cont’d) Near-mine and District Opportunities 48 Mantos Blancos Block • Exploration Geophysics to identify appropriated volcanic rock (mineralized) package at depth and under the cover • High resolution drone mag + Ambient Noise Tomography (Seismic) survey Rosario Block • Follow-up geochem and magnetic anomaly in southern Domain B Domain B Domain A Follow-up on geochemical anomalies generated in 2023 stream sediment and historic geochem program mine Rosario Block Mantos Blancos Block prospective geology? mine Rosario Block Mantos Blancos Block 5 km 2.5 km Geophysics exploration to identify appropriated volcanic rock (mineralized) package at depth and under the cover. ANT survey (seismic) example Magnetics RTP Regional Sulphide/Oxide Deposits 48
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC • Globe-Miami is one of the oldest and most productive mining districts in the US • First recorded production occurred in 1878 since then, +15 billion lbs Cu have been produced • Since 1975, Pinto Valley has produced +4 billion lbs Cu, including ~0.5 billion lbs of cathode • Pinto Valley is currently the second largest employer in the area; total economic impact in Arizona is +$270 million per year • Measured and Indicated Mineral Resource1 base of 1 billion tonnes, currently not in Mineral Reserve, has the potential to create long-term sustainable benefits for multiple generations BHP Copper Cities KGHM Carlota Mine Carlota SX-EW 70M Ibs/yr Pinto Valley Mine PV SX- EW 25M Ibs/yr PV ~60k tpd Mill BHP Miami SX-EW 30M Ibs/yr TJ Pit Historic Freeport Miami Mine • Exploration Access Agreement with BHP for Copper Cities from January 2022 through July 2025 • $7M two-phase drill program to twin drill historical holes completed • Less than 10km from Pinto Valley Mine Copper Cities 1 Refer to Appendix slides “Capstone Copper Consolidated Estimated Mineral Resources” and “Capstone Copper Consolidated Estimated Mineral Reserves” and the Annual Information Form for the year ended December 31, 2025 for full details. 2 Refer to the news release dated January 20, 2022 entitled “Capstone Enters into Exploration Access Agreement with BHP Copper Inc. for Copper cities Project” and the news release of June 13, 2021 entitled “Capstone Copper Provides an Update on its Global Exploration Program“ Pinto Valley: District Consolidation Potential 49
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC • Proven BPA ion-exchange technology • Commonly used in Ni/Co industry • Selective for Co/Ni but requires Cu and Fe3+ removal • Does not require acid neutralization • Continuous Counter-Current Ion Exchange (CCIX) • Flexible process conditions • Multiple adsorption passes • Multiple elution phases can be readily implemented • Maximizes utilization of resin / mass transfer zone Proven Extraction Technology MV-SD Pyrite Augmentation & Cobalt Opportunity Heap Leach Ion-Exchange to Recover Cobalt Co 27 Cobalt 50 Integration with Santo Domingo Next Steps • On-site piloting of CCIX process commenced in Q1/24 • Engineering study expected in 2025, including: • Pyrite recovery • Bacterial augmentation and heap aeration • IX facility • Packaging & sales Planned Co Plant Planned PLS / Raffinate Lines Planned Pyrite Concentrate Pipeline Mantoverde Santo Domingo Addition of pyrite to our heap leach operations has the opportunity to reduce MV sulphuric acid requirements by over 20%
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 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. Mineral Resources are reported inclusive of the Mineral Reserves. All Mineral Resources are exclusive to dilution and mining recovery factors. All contained metals are reported at 100% except as stated. Rounding as required by reporting guidelines may result in apparent summation differences between tonnes, grade and contained metal content. Grade TCu% refers to total copper grade in percent sent to the mill for metallurgical recovery by flotation. Grade SCu% refers to soluble copper grade in percent sent to the leaching processes. Grade ICu% refers to insoluble copper grade in percent, based on TCu% minus SCu%. Contained ounces (oz) are troy ounces. COG is cut-off grade. NSR is net smelter return. M&I = Measured & Indicated. All amounts in US$ unless otherwise specified. Stockpiled material is treated as Mineral Resources, described below. See Technical Reports filed under Capstone Copper’s profile on SEDAR+ for further information. 1. Garth Kirkham, P.Geo., FGC is the Qualified Person responsible for the Mineral Resource presented in the Pinto Valley Mine Technical Report, effective March 31, 2021. Klaus Triebel, GPG, Chief Resource Modeler at Pinto Valley Mine, oversaw depletion of the of Mineral Resource for mining activities as at December 31, 2023. Mineral Resources are reported at a 0.14% Cu cut-off grade. Economic assumptions for the reasonable prospects pit include: $3.50/lb Cu, $10.00/lb Mo, 84.6% Cu recovery, 8.9% Mo recovery, $1.74/tonne mining costs, $1.13/tonne G&A costs, $0.88/tonne operational support costs, $4.67/tonne milling costs, and pit slopes by rock type. Stockpile material is included as Measured Mineral Resource. Pinto Valley Mine is an open-pit mine with mineral processing by flotation. 2. Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper is the Qualified Person responsible for the Mineral Resource in the Cozamin Mine Technical Report, effective January 1, 2023, and the depletion of the Mineral resource for mining activities as at December 31, 2024. Mineral resources are reported at a cut-off of NSR US$59/tonne. Metallurgical recoveries used in the NSR formulae are based on mineralization. Metallurgical recoveries vary by domain and NSR formula. Copper-silver dominant zones use the NSR formula: (Cu%*$70.72 + Ag g/t$0.53) * (1-NSR Royalty%). Copper-silver dominant zones use the following metallurgical recoveries: 96.16% Cu and 85.83% Ag. Copper–zinc zones use the NSR formula: (Cu%*$69.74 + Ag g/t*$0.50 + Zn%*$12.96) * (1-NSR Royalty%). Copper-zinc zones use the following metallurgical recoveries: 94.82% Cu, 83.82% Ag, 66.95% Zn, and 0% Pb. MNFWZ zinc–silver dominant zones use the NSR formula: (Ag g/t*$0.35 + Zn%*$16.80 + Pb%*$15.11) * (1-NSR Royalty%). Zinc–silver dominant zones use the following metallurgical recoveries: 66.50% Ag, 86.79% Zn, and 92.86% Pb. The NSR formula for MNV zinc zones is (Ag*0.241 + Zn*15.511 + Pb*12.993)*(1-NSRRoyalty%) using metallurgical recoveries of 55% Ag, 80% Zn and 80% Pb. The NSR formula for MNV copper-zinc zones is (Cu*69.739 + Ag*0.498 + Zn*12.956)*(1-NSRRoyalty%) using metallurgical recoveries of 95% Cu, 85% Ag and 67% Zn. The formulae include consideration of confidential current smelter contract terms, transportation costs and 1-3% net smelter return royalty payments. Metal price assumptions (in US$) used to calculate the NSR for all deposits are: $3.75/lb Cu, US$22.00/oz Ag, US$1.35/lb Zn and US$1.00/lb Pb. An exchange rate of MX$20 per US$1 is assumed. The NSR cut-off is based on operational mining and milling costs plus general and administrative costs. The Mineral Resource Estimate encompasses both the MNFWZ and the MNV. The Mineral Resource was estimated assuming underground mining by longhole stoping and post-pillar cut-and-fill with mineral processing by flotation. Mineral Resource estimates do not account for mining loss and dilution. All metals are reported as contained. 3. Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Resource estimates for the Santo Domingo, Iris, Iris Norte and Estrellita deposits, effective March 31, 2024. Mineral Resources for the Santo Domingo, Iris and Iris Norte deposits are reported using a net smelter return (NSR) cut-off value of US$9.85/t. NSR is calculated using average long-term prices of US$4.10/lb Cu, US$1,600/oz Au, and Fe prices that depend on the expected grade of the Fe concentrate (US$94.75/dmt or $129.77/dmt or $140.26/dmt Fe concentrate). Mineral Resources are constrained by preliminary pit shells derived using a Lerchs–Grossmann algorithm and the following assumptions: pit slopes 36.3°- 47.9°; mining cost is calculated using a function that depends on where the material comes from (Santo Domingo or Iris Norte) and its destination (dumps, plant or stock); processing cost based on Fe concentrate routing code (including G&A costs); processing recovery based in the recovery equations for copper, gold, and iron as detailed above. For the Estrellita deposit,Mineral Resources are reported using an NSR cut-off value of US$9.63/t. NSR is calculated using average long-term prices of US$4.10/lb Cu and US$1,600/oz Au; only copper, and gold were considered in the NSR calculation(iron was excluded). Estrellita Mineral Resources are constrained by preliminary pit shells generated using a Lerchs–Grossmann algorithm and the following assumptions: pit slopes 43º; mining cost of US$1.55/t, processing cost of US$9.46/t (including G&A cost); processing recovery are calculated based in the recovery curves for copper and gold. The average Iron grades for the Project (Total Indicated, Total Measured plus Indicated, and Total Inferred Resources) cannot be calculated because Estrellita does not contain iron resources. 4. Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Resource estimates at the Mantoverde Mine effective December 31, 2024. Mineral Resources are reported on a 100% basis. The attributable percentage to Capstone Copper is 69.993%. COG varies per zone and recovery process:Flotation: Sulphide: TCu ≥ 0.20% and oxidation state=3, Mixed: TCu ≥ 0.20% and SCu/TCu ≤ 50% and oxidation state=2.Dump Leach: Oxide: 0.10% ≤ SCu < 0.20% and oxidation state=1, Mixed 0.10% ≤ SCu < 0.20% and SCu/TCu > 50% and oxidation state=2.Heap Leach: Oxide: SCu ≥ 0.20% and oxidation state=1, Mixed: SCu ≥ 0.20% and SCu/TCu > 50% and oxidation state=2.Flotation recovery is based on a geometallurgical model, 90.44%TCu and 67.87% Au average for Sulphides and 72.77% TCu and 61.73% Au average for Mixed. Heap Leach recovery is based on operating data, expressed in algorithms per mineral model zone considering both SCu and CaCO₃ grades. The average heap leach recovery is 67.64% SCu, with an additional 50% metal recovered achieved through the bioleaching process. For dump leaching, the recovery averages 38.9% SCu, based on operational data. Dump recovery is 37.74%SCu (based on operating data). The Mineral Resource pit is based on $4.00/lb Cu and $1,700/oz Au based on long-term forecast pricing. 5. Ronald Turner, MAusIMM (CP), a WSP employee, is the independent Qualified Person responsible for the Mineral Resource in the Mantos Blancos Mine Technical Report effective November 29, 2021. Luis Tapia Hurtado, CP CMC, Resource and Reserve Evaluation Geologist at Mantos Copper, oversaw depletion of the Mineral Resource for mining activities as at December 31, 2024 with Direct Supervision by Guillermo Pareja, P.Geo. Mineral Resources are reported on a 100% basis. The attributable percentage to Mantos Copper Holding SpA is 99.993%. COG varies by metallurgical process: Flotation at 0.22% Insoluble Cu, Dump Leach at 0.10% Soluble Cu. The Mineral Resource pit is based on US$3.75/lb Cu and US$20.00/oz Ag. Flotation recovery is based on a geometallurgical model, 83.4% TCu and 70.7% Ag as average. Dump recovery is based on average operational data at 42.4% SCu. Through the Osisko silver production agreement, Osisko Gold has the right to buy 100% of the silver production in concentrate, less specified deductions, until reaching 19.3 million ounces and subsequently 40% paying 92% of the market price. The stockpile includes 3,490 kt of Indicated Mineral Resource at 0.44% TCu. TCu SCu Zn Pb Mo Ag Au Fe Co S Cu Zn Pb Mo Ag Au Fe3 Co3 % % % % % g/t g/t % ppm % kt kt kt kt koz koz mt kt Pinto Valley1 Measured 591,760 0.33 - - - 0.006 - - - - - 1,941 - - 36 - - - - 31-Dec-2024 Indicated 762,630 0.26 - - - 0.005 - - - - - 2,006 - - 38 - - - - M&I 1,354,391 0.29 - - - 0.005 - - - - - 3,947 - - 74 - - - - Inferred 149,793 0.27 - - - 0.006 - - - - - 410 - - 9 - - - - Cozamin2 Measured 400 1.25 - 1.23 0.40 - 53.8 - - - - 5 5 2 - 692 - - - 31-Dec-2024 Indicated 19,208 1.39 - 1.12 0.41 - 44.3 - - - - 268 215 79 - 27,377 - - - M&I 19,608 1.39 - 1.12 0.41 - 44.5 - - - - 273 220 80 - 28,069 - - - Inferred 13,634 0.72 - 1.83 0.75 - 38.9 - - - - 98 249 102 - 17,054 - - - Measured 134,000 0.51 - - - - - 0.07 26.9 - - 679 - - - - 293 36 - Indicated 413,000 0.25 - - - - - 0.03 n/a - - 1,025 - - - - 449 95 - 31-Mar-2024 M&I 547,000 0.31 - - - - - 0.04 n/a - - 1,704 - - - - 742 131 - Inferred 230,000 0.21 - - - - - 0.03 n/a - - 477 - - - - 200 46 - Mantoverde4 Measured 185,499 0.57 - - - - - 0.10 - 179 - 1,057 - - - - 596 - 33 Sulphides Indicated 329,324 0.41 - - - - - 0.10 - 134 - 1,350 - - - - 1,058 - 44 (Flotation) M&I 514,823 0.47 - - - - - 0.10 - 150 - 2,407 - - - - 1,654 - 77 Inferred 553,070 0.37 - - - - - 0.08 - 62 - 2,046 - - - - 1,423 - 34 Sulphides Mixed Measured 36,350 0.47 - - - - - 0.09 - 87 - 171 - - - - 105 - 3 (Flotation) Indicated 37,263 0.37 - - - - - 0.09 - 103 - 139 - - - - 108 - 4 M&I 73,613 0.42 - - - - - 0.09 - 95 - 310 - - - - 213 - 7 Inferred 17,781 0.29 - - - - - 0.06 - 30 - 52 - - - - 34 - 1 Oxides + Mixed Measured 97,226 0.46 0.35 - - - - - - - - 340 - - - - - - - (Heap Leach) Indicated 61,945 0.40 0.30 - - - - - - - - 186 - - - - - - - M&I 159,171 0.44 0.33 - - - - - - - - 526 - - - - - - - Inferred 11,168 0.37 0.28 - - - - - - - - 31 - - - - - - - Oxides + Mixed Measured 148,074 0.22 0.15 - - - - - - - - 222 - - - - - - - (Dump Leach) Indicated 149,594 0.21 0.14 - - - - - - - - 209 - - - - - - - M&I 297,668 0.21 0.14 - - - - - - - - 431 - - - - - - - 31-Dec-2024 Inferred 58,610 0.22 0.14 - - - - - - - - 82 - - - - - - - Mantos Blancos5 Measured 81,704 0.73 - - - - 5.64 - - - - 596 - - - 14,815 - - - Sulphides + Mixed Indicated 95,434 0.57 - - - - 4.18 - - - - 539 - - - 12,832 - - - (Flotation) M&I 177,138 0.64 - - - - 4.85 - - - - 1,135 - - - 27,647 - - - Inferred 13,768 0.48 - - - - 3.74 - - - - 66 - - - 1,656 - - - Oxides + Mixed Measured 17,339 - 0.35 - - - - - - - - 61 - - - - - - - (Dump Leach) Indicated 98,925 - 0.16 - - - - - - - - 159 - - - - - - - M&I 116,264 - 0.19 - - - - - - - - 220 - - - - - - - 31-Dec-2024 Inferred 20,411 - 0.17 - - - - - - - - 35 - - - - - - - 10,952 220 80 74 55,717 2,609 131 84 3 298 249 102 9 18 710 1 657 46 35 Santo Domingo3 TOTAL MEASURED & INDICATED MINERAL RESOURCES TOTAL INFERRED MINERAL RESOURCES MINERAL RESOURCES – Inclusive of Mineral Reserves CONTAINED METAL Category kt 51
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Consolidated Estimated Mineral Reserves NOTES: Mineral Reserves take into account mining activities as stated, where applicable. Rounding as required by reporting guidelines may result in apparent summation differences between tonnes, grade and contained metal content. Grade TCu% refers to total copper grade in percent sent to the mill for metallurgical recovery by flotation. Grade SCu% refers to soluble copper grade in percent sent to the leaching processes. Grade ICu% refers to insoluble copper grade in percent, based on TCu% minus SCu%. All Mineral Reserve estimates take into account dilution and mining recovery factors. Contained ounces (oz) are troy ounces. COG is cut-off grade. NSR is net smelter return. All amounts in US$ unless otherwise specified. Stockpiled material is included in the Mineral Reserves, described below. See Technical Reports filed under Capstone Coppers’s profile on SEDAR+ for further information. 1. Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, is the Qualified Person responsible for the Pinto Valley Mineral Reserve estimate as at December 31, 2024. Economic inputs to the block model were $3.00/lb per pound copper, $10.00/lb molybdenum, 86.0% average Cu recovery, 8.5% average Mo recovery, $1.68/tonne average mining costs, $1.13/tonne G&A costs, $0.88/tonne Ops Support costs, $4.67/tonne milling costs, and pit slopes by rock type. The Mineral Reserve is reported at a COG of 0.19% copper. Stockpiled material is included as Proven Mineral Reserve. Pinto Valley Mine is an open-pit mine with mineral processing by flotation. 2. Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, is the Qualified Person for the Cozamin Mine Mineral Reserve as at December 31, 2024. The Mineral Reserve is reported within fully diluted mineable stope shapes generated by the Deswik Mineable Shape Optimiser software. Mining methods include long-hole stoping and cut-and-fill methods. The Mineral Reserve is reported at or above a blended cut-off of US$60.54/t NSR for long-hole stoping, US$65.55/t NSR for cut-and-fill methods, and US$82.78/t NSR for MNV West cut-and-fill and long-hole stoping. The NSR cut-off is based on operational mining and milling costs plus general and administrative costs. The NSR formulae vary by zone. Four separate NSR formulae are used based on zone mineralization and metallurgical recoveries. Copper-silver dominant zones use the NSR formula: (Cu*66.638 + Ag*0.484)*(1-NSRRoyalty%), except the MNV West copper-silver zone, which uses the formula (Cu% * $70.724 + Ag g/t * $0.484) * (1-NSRRoyalty%)). MNFWZ zinc-silver zones use the NSR formula: (Ag*0.290 + Zn*13.723 + Pb*13.131)*(1-NSRRoyalty%). MNV zinc- silver dominant zones use the NSR formula: (Ag*0.228 + Zn*12.121 + Pb*11.363)*(1-NSRRoyalty%). Metal price assumptions of Cu = US$3.55/lb for MNV and MNFWZ, Cu $3.75/lb for MNV West, Ag = US$20.00/oz, Pb = US$0.90/lb, Zn = US$1.15/lb and metal recoveries of 96% Cu, 86% Ag, 0% Pb and 0% Zn in copper-silver dominant zones, 0% Cu, 61% Ag, 93% Pb and 88% Zn in MNFWZ zinc-silver dominant zones, and 0% Cu, 56% Ag, 80% Pb and 77% Zn in MNV zinc-silver dominant zones. The formulae include consideration of confidential current smelter contract terms, transportation costs and 1–3% net smelter return royalty payments. Royalties are dependent on the mining concession, and are treated as costs in the Mineral Reserve estimates. Totals may not sum due to rounding. 3. Peter Amelunxen, P.Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Santo Domingo Project Mineral Reserve effective March 31, 2024. Mineral Reserves are reported as constrained within Measured and Indicated Resources and pit designs optimized using the following economic and technical parameters: metal prices of US$3.75/lb Cu, US$1,400/oz Au and Fe prices ranging from US$69/dmt to US$114.51/dmt based on the Fe grade in concentrate (net of Fe concentrate transport costs); average recovery to concentrate is 90.1% for Cu and 56.3% for Au, with magnetite concentrate recovery varying on a block-by-block basis; copper concentrate treatment charges of US$80/dmt, U$0.08/lb of copper refining charges, US$5.0/oz of gold refining charges, US$40/wmt and US$25.75/dmt for shipping copper and iron concentrates respectively; waste and ore mining cost of $1.55/t and process and G&A+SUSEX of US$9.77/t processed; average pit slope angles that range from 36.3° to 47.9°; a 2% royalty rate assumption and an assumption of 100% mining recovery. No formal production has occurred from the Santo Domingo property area. 4. Peter Amelunxen, P. Eng., Senior Vice President, Technical Services at Capstone Copper is the Qualified Person responsible for the Mineral Reserve at the Mantoverde Mine effective December 31, 2024. Mineral Reserves are reported on a 100% basis as constrained within Measured and Indicated Resources and pit designs included within the mine schedule. The attributable percentage to Capstone Copper is 69.993%. The block model is considered to be fully diluted and no dilution or mining losses are applied. The pit designs and mine plan were optimized using assumed metal prices of $3.50/lb Cu and $1,500/oz Au. Mineral Reserves for flotation are estimated above a 0.20% Total Copper (TCu) cut-off. Mineral Reserves for leach are estimated above a 0.10% Soluble Copper (SCu) cut-off for Dump leach, with a variable Heap cut-off between 0.16% and 0.21% SCu to reflect ore availability. Leach-grade material mined after 2037 was scheduled as waste. LOM feed to flotation averaged 87.7% total copper recovery and 65.3% gold recovery. Average heap leach recovery applied in Mine Planning was 71.5% of SCu and 50% of ICu, where ICu = TCu – SCu. Average dump leach recovery applied was 38.0% of SCu. Mineral Reserves considered the following average costs: mining cost of $1.87 per tonne moved; $10.11/t flotation processing+tails+G&A; $0.31/lb TC/RC+freight for flotation; $10.14/t heap+G&A; $1.78/t dump leach; $0.35/lb SX/EW costs; and $0.05/lb cathode selling cost. Heap leach Reserve figures include the costs and benefits of bioleaching; the contained metal reported in the table considers SCu only. This excludes insoluble copper, of which a portion is expected to be recovered from bioleaching in the heap leach process. Inter-ramp angles in rock vary from 52° to 59°. The LOM strip ratio is 2.7:1. 5. Carlos Guzman, RM CMC, FAusIMM, an employee of NCL, is the independent Qualified Person responsible for the Mineral Reserve in the Mantos Blancos Technical Report effective November 29, 2021. Clay Craig, P.Eng., Director, Mining & Strategic Planning at Capstone Copper, oversaw depletion of the Mineral Reserve for mining activities as at December 31, 2024. The Mineral Reserve is based on average off-site costs (selling cost) of US$0.297/lb for sulphides and US$0.60/lb for oxides. Mineral Reserves are contained within an optimized pit shell. The estimated Mineral Reserves are reported using metal prices of US$3.50/lb Cu and US$20/oz Ag. Mining will use conventional open pit methods and equipment and a stockpiling strategy (direct mining costs are estimated at an average US$1.99/t of material mined). Processing costs average US$14/t of milled material, including concentrator, tailings storage facility and port costs. Processing cost for material sent to dump leach is US$2.26/t. TCu recovery averages 83.1% for sulphides and silver recoveries average 79.5%. SCu recovery of 42% was used in mine planning for material sent to the dump leach. Inter-ramp angles vary from 36˚ to 54˚in the sulphide zones and from 31˚ to 36˚ in the oxide zones . The life-of-mine strip ratio is 4.2 to 1 for the sulphide zones and 4.4 to 1 in the oxide zones. Through the Osisko silver production agreement, Osisko Gold has the right to buy 100% of the silver production in concentrate (less specified deductions) until reaching 19.3 million ounces and subsequently 40% paying 92% of the market price. Stockpiled material is included in the Probable Mineral Reserve. 52 TCu SCu ICu Zn Pb Mo Ag Au Fe Cu Zn Pb Mo Ag Au Fe3 % % % % % % g/t g/t % kt kt kt kt koz koz Mt Pinto Valley1 Proven 216,001 0.34 - - - - 0.007 - - - 726 - - 15 - - - 31-Dec-2024 Probable 103,885 0.28 - - - - 0.006 - - - 292 - - 6 - - - Total 319,886 0.32 - - - - 0.007 - - - 1,017 - - 21 - - - Cozamin2 Proven - - - - - - - - - - - - - - - - - 31-Dec-2024 Probable 8,084 1.52 - - 0.64 0.36 - 43.0 - - 123 52 29 - 11,181 - - Total 8,084 1.52 - - 0.64 0.36 - 43.02 - - 123 52 29 - 11,181 - - Santo Domingo3 Proven 130,945 0.52 - - - - - - 0.07 27.2 675 - - - - 291 13 Probable 305,111 0.25 - - - - - - 0.04 26.2 761 - - - - 346 56 31-Mar-2024 Total 436,056 0.33 - - - - - - 0.05 26.5 1,435 - - - - 637 68 Mantoverde4 Proven 213,176 0.56 - - - - - - 0.10 - 1,194 - - - - 685 - Sulphides + Mixed Probable 182,299 0.40 - - - - - - 0.09 - 729 - - - - 527 - (Flotation) Total 395,475 0.49 - - - - - - 0.10 - 1,923 - - - - 1,213 - Oxides Proven 136,813 0.30 0.21 - - - - - - - 287 - - - - - - (Dump+Heap Leach) Probable 84,860 0.27 0.19 - - - - - - - 161 - - - - - - 31-Dec-2024 Total 221,673 0.29 0.21 - - - - - - - 449 - - - - - - Mantos Blancos5 Proven 57,000 0.75 0.09 0.66 - - - 6.02 - - 427 - - - 11,029 - - Sulphides + Mixed Probable 47,948 0.51 0.07 0.44 - - - 3.95 - - 246 - - - 6,089 - - (Flotation) Total 104,948 0.64 0.08 0.55 - - - 5.07 - - 673 - - - 17,118 - - Oxides + Mixed Proven 1,706 0.48 0.33 - - - - - - - 6 - - - - - - (Dump Leach) Probable 1,339 0.34 0.22 - - - - - - - 3 - - - - - - 31-Dec-2024 Total 3,046 0.43 0.28 - - - - - - - 9 - - - - - - 5,628 52 29 21 28,299 1,850 68TOTAL MINERAL RESERVES MINERAL RESERVES CONTAINED METAL Category kt
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC Sierra Norte Historical Mineral Resources 53 Category Tonnes (Mt) CuT % CuS % Copper (kt) Carmen-Paulina Measured 7.5 0.47% 0.16% 35.5 Indicated 63.5 0.46% 0.10% 292.0 Inferred 25.1 0.40% 0.04% 101.5 Total 96.1 0.45% 0.09% 429.0 Esther Measured 0.7 0.42% 0.26% 3.0 Indicated 3.3 0.40% 0.24% 13.3 Inferred 0.1 0.35% 0.22% 0.3 Total 4.1 0.40% 0.24% 16.6 Economic Parameters for Mineral Resources: • Copper price: $3.00/lb • Mining cost: $1.69/t • Processing • Sulphide recovery: 91% • Sulphide processing cost: $7.26/t • Oxide (heap) recovery: 60% • Oxide (heap) processing cost: $8.12/t • Oxide (SX-EW) processing cost: $0.30/lb • Selling Costs • Concentrates: $0.41/lb • Cathodes: $0.04/lb Notes: 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 Wheeler with an effective date on April 29, 2016 prepared for Alxar S.A. The historical estimates are strictly historical in nature and are non compliant with NI 43-101 and should not be relied upon. A qualified person has not done sufficient work to classify the historical estimates as current “mineral resources”, as such term is defined in NI 43-101 and it is uncertain whether, following further evaluation or exploration work, the historical estimates will be able to report as mineral resources in accordance with NI 43-101. Capstone has not done sufficient work to classify the historical estimate as current mineral resources and is not treating the historical estimate as current mineral resources. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Mineral Resources reported using a cut-off grade of 0.2% with further economic extraction parameters outlined below. Mineral Resources reported by category; based on average spacing of drillholes and levels of confidence in the grade estimation. There are no more recent estimates or data available to Capstone. The Sierra Norte deposit will require further evaluation including drilling to verify the historical estimate as current mineral resources. Investors are cautioned not to place undue reliance on the historical estimates contained in this news release.
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CAPSTONE COPPER CORP. | TSX:CS | ASX:CSC 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 Slifirski, Director, Investor Relations, APAC Region (+61) 412-251-818, Melbourne, Australia Claire Stirling, Manager, Investor Relations +1-416-831-8908, Toronto, ON info@capstonecopper.com