Capstone Copper Reports First Quarter 2024 Results

All amounts in US$ unless otherwise indicated

Capstone Copper Corp. ("Capstone" or the "Company") (TSX: CS) (ASX: CSC) today reported financial results for the three months and quarter ended March 31, 2024 ("Q1 2024"). Copper production in Q1 totaled 42,121 tonnes at C1 cash costs¹ of $2.88 per payable pound of copper produced. Link HERE for Capstone's Q1 2024 webcast presentation.

John MacKenzie, CEO of Capstone, commented, "Our mines got off to a solid start in the first quarter as we executed on our operating plans and delivered strong financial results. The copper market has entered into the early stages of a new era, and we are positioned extremely well as our flagship Mantoverde mine ramps up to full production. During the quarter, we advanced the feasibility studies that we plan to release by mid-year for our MV-Optimized brownfield expansion and our nearby Santo Domingo project, defining the next significant phases of our value-accretive production growth. Additionally, we are planning an exploration program focused on our highly prospective Mantoverde-Santo Domingo land package, that we believe will further demonstrate the world-class nature of the district."

Q1 2024 OPERATIONAL AND FINANCIAL HIGHLIGHTS

• Consolidated copper production for Q1 2024 was 42,121 tonnes at C1 cash costs¹ of $2.88/lb, which consisted of 15,672 tonnes at Pinto Valley, 10,967 tonnes at Mantos Blancos, 9,476 tonnes at Mantoverde, and 6,006 tonnes at Cozamin.
• Net loss attributable to shareholders of $4.8 million, or $(0.01) per share for Q1 2024 compared to net loss attributable to shareholders of $20.0 million, or $(0.03) per share for Q1 2023.
• Adjusted net loss attributable to shareholders¹ of $4.5 million, or $(0.01) per share for Q1 2024. Q1 2024 adjusted net loss attributable to shareholders¹ is lower than Q1 2023 adjusted net income attributable to shareholders¹ of $17.5 million due to lower realized copper price.
• Adjusted EBITDA¹ of $80.1 million for Q1 2024 compared to $66.0 million for Q1 2023. The increase in Adjusted EBITDA¹ is driven by higher copper sold (41.0 thousand tonnes in Q1 2024 versus 37.5 thousand tonnes in Q1 2023), partially offset by a lower realized copper price of $3.86/lb compared to $4.12/lb (prior to unrealized provisional pricing adjustments).
• Operating cash flow before changes in working capital of $62.1 million in Q1 2024 compared to $41.7 million in Q1 2023.
• At the Mantoverde Development Project ("MVDP"), the Company has continued to systematically commission the concentrator plant with first saleable concentrate expected in Q2 2024. First ore was introduced to the grinding circuit during March, which represents the completion of a key commissioning event. Project total capital remains unchanged at $870 million. Capstone is focused on a safe, efficient and phased project commissioning and ramp-up.
• In February 2024, the Company and Orion Fund JV Limited, Orion Mine Finance Fund II LP and Orion Mine Finance (Master) Fund I-A LP (collectively, "Orion") closed a bought deal financing with a syndicate of underwriters ("the Offering"). In connection with the Offering, 56.5 million common shares were issued by the Company with a value of C$6.30 per common share raising total proceeds, net of transaction costs, of $252.9 million. As part of the Offering, Orion completed a secondary sale of 11.9 million common shares.
• On February 2, 2024, the Company's secondary listing on the Australian Securities Exchange commenced trading under the ticker symbol "CSC".
• On April 5, 2024, the Company and Orion announced that Orion entered into a block trade agreement to sell 62.4 million CHESS depository interests ("CDIs") of Capstone (or the equivalent of 62.4 million fully paid Common Shares of Capstone) at a price of A$9.50 per CDI, for gross proceeds to Orion of approximately A$592.8 million. Post transaction, Orion owns 90.5 million common shares, representing approximately 12.0% of the outstanding common shares of Capstone.
• Net debt¹ decreased significantly from $927.2 million as at December 31, 2023, to $740.2 million as at March 31, 2024. Total available liquidity¹ of $539.8 million as at March 31, 2024, composed of $131.8 million of cash and short-term investments, and $408.0 million of undrawn amounts on the corporate revolving credit facility.
• The Company reiterates the 2024 guidance of 190,000 to 220,000 tonnes of copper at C1 cash costs of $2.30/lb to $2.50/lb, including the H1 and H2 guidance ranges previously disclosed. Total 2024 sustaining and expansionary capital expenditure guidance of $275 million, plus an additional $180 million for capitalized stripping, is also reaffirmed.
• The company envisions commencing in H2 2024 an initial two-year $25 million exploration program at Mantoverde aimed at: i) targeting higher copper grades; ii) increasing reserves and resources near the Mantoverde pits; and iii) testing high priority district targets in the northern part of the Mantoverde land package.

OPERATIONAL OVERVIEW

Refer to Capstone's Q1 2024 MD&A and Financial Statements for detailed operating results.

Consolidated Production

Q1 2024 consolidated production of 42,121 tonnes of copper was 3% higher than 40,734 tonnes in Q1 2023, due to higher production at Pinto Valley and Cozamin mainly on higher grades, and at Mantoverde on higher grades and recoveries, partially offset by lower production at Mantos Blancos.

Q1 2024 C1 cash costs¹ of $2.88/lb were 3% lower than $2.96/lb Q1 2023 on higher copper production along with lower main consumables prices and cost saving initiatives.

Pinto Valley Mine

Q1 2024 production was 22% higher than Q1 2023 due to significantly higher mill feed grade (0.36% in Q1 2024 versus 0.30% in Q1 2023) and higher recoveries (87.7% Q1 2024 versus 86.8% Q1 2023).

Q1 2024 C1 cash costs¹ of $2.53/lb were 18% lower compared to the same period last year of $3.09/lb primarily due to higher production volume in the quarter ($0.56/lb) along with lower costs on grinding media and diesel from favorable pricing contracts executed in 2024 ($3.31/gal in Q1 2024 versus $3.70/gal in Q1 2023), lower property taxes and insurance costs, partially offset by increased mining costs due to spend on equipment maintenance and inflationary increases for electricity cost ($0.067/kWh in Q1 2024 versus $0.057/kWh in Q1 2023).

Mantos Blancos Mine

Q1 2024 production of 11.0 thousand tonnes, composed of 9.2 thousand tonnes from sulphide operations and 1.8 thousand tonnes of cathodes from oxide operations, was 22% lower than Q1 2023 on lower mill throughput (14,214 tpd in Q1 2024 versus 16,023 in Q1 2023) primarily due to a planned mill shutdown in February in order to prepare for installation of new equipment needed to achieve 20,000 tpd capacity and lower feed grades as a result of mine sequence (0.87% in Q1 2024 versus 0.94% in Q1 2023). To a lesser extent, the results were also impacted by unplanned maintenance. Cathode production in Q1 2024 was 45% lower than Q1 2023 due to lower throughput in line with the 2024 plan.

Combined Q1 2024 C1 cash costs¹ of $3.05/lb ($2.98/lb sulphides and $3.43/lb cathodes) were 14% higher compared to $2.68/lb in Q1 2023 mainly due to lower production ($0.78/lb), partially offset by lower key consumable prices (-$0.15/lb), lower acid and energy consumption due to lower production (-$0.12/lb) and lower mine movements (-$0.14/lb). Realized sulphuric acid prices averaged $154/t in Q1 2024 versus $212/t in Q1 2023, energy prices averaged $0.10/kWh in Q1 2024 versus $0.11/kWh in Q1 2023, and diesel prices averaged $0.76/l in Q1 2024 versus $0.84/l in Q1 2023.

Mantoverde Mine

Q1 2024 production of 9.5 thousand tonnes was 11% higher than Q1 2023 due to higher heap grades as a result of mine sequence (0.36% in Q1 2024 versus 0.31% in Q1 2023) and higher recoveries (74.9% in Q1 2024 versus 69.0% in Q1 2023) due to higher solubility ratio of the processed mineral. Heap throughput in Q1 2024 was consistent with the same period last year. Dump production in Q1 2024 was 26% lower than Q1 2023 mainly on lower grades and recoveries due to mine sequence.

Q1 2024 C1 cash costs¹ were $3.82/lb, 5% lower than $4.02/lb in Q1 2023 mainly related to higher production (-$0.40/lb) and lower main consumable prices (-$0.66/lb), which was partially offset by higher operational mine costs ($0.26/lb) and mine movement/stripping ($0.49/lb) due to change in mine sequence. Realized sulphuric acid prices averaged $145/t in Q1 2024 versus $177/t in Q1 2023, energy prices averaged $0.10/kWh in Q1 2024 versus $0.26/kWh in Q1 2023, and diesel prices averaged $0.74/l in Q1 2024 versus $0.83/l in Q1 2023. Energy costs significantly decreased as a result of a new long-term energy contract that commenced from January 1, 2024.

Cozamin Mine

Q1 2024 production was 15% higher than Q1 2023 due to higher grades (1.98% in Q1 2024 versus 1.77% in Q1 2023) consistent with the mine plan. Throughput and recoveries were consistent with the same period last year.

Q1 2024 C1 cash costs¹ were 12% higher than the same period last year primarily due to the change in mining method which resulted in an increase in contractor utilization ($0.18/lb) and unfavourable foreign exchange rate ($0.10/lb), partially offset by more pounds payable produced and higher silver by-products credits.

Mantoverde Development Project

During Q1 2024, the Company advanced commissioning activities at the Mantoverde Development Project in Chile. The Company is focused on a safe, efficient and phased project commissioning and ramp-up. Notably, first ore was introduced to the grinding circuit (principally the SAG and Ball mills) during March, and the project remains on track for first saleable concentrate during Q2 2024.

MVDP is expected to enable the mine to process 236 million tonnes of copper sulphide reserves over a 20-year expected mine life, in addition to existing oxide reserves. The MVDP involves the addition of a sulphide concentrator (nominal 32,000 ore tonnes per day) and tailings storage facility, and the expansion of the existing desalination plant and other minor infrastructure.

MVDP is progressing under a lump-sum turn-key engineering, procurement, and construction (EPC) contract with Ausenco Limited, a multi-national EPC management company, with broad international experience in the design and construction of copper concentrator projects of this scale in the international market. The execution plan includes a Capstone Copper owner's team working with Ausenco during the execution phase. The contract with Ausenco includes the project commissioning and ramp-up.

Key milestones during the commissioning and ramp-up include:

1. First ore to the primary crusher - completed in Q4 2023
2. First ore to the grinding circuit - completed in Q1 2024
3. First saleable concentrate - on track for Q2 2024
4. Achievement of nameplate operating rates - expected during Q3 2024

As of March 31, 2024, cash capital spent at MVDP totaled $823 million versus the project capital estimate of $870 million.

A virtual tour of MVDP can be viewed at https://vrify.com/decks/12698-mantoverde-development-project

MV Optimized Feasibility Study and Phase II

The Company is currently analyzing the next expansion of the sulphide concentrator and the optimization of the heap leach and solvent extraction facilities. Capstone has identified that the desalination plant capacity and major components of the comminution and flotation circuits of the MVDP can sustain an average annual throughput of approximately 45,000 tonnes per day. Capstone is working with Ausenco and Global Resource Engineering Ltd to develop the MV Optimized Feasibility Study, including evaluating the costs and timelines of debottlenecking the minor components of the plant to meet the potential increased throughput target. Completion of the optimized feasibility study is expected in the first half of 2024. The Company recently submitted an environmental DIA permit application for the MV Optimized project.

Given the above, the Mantoverde Phase II opportunity will evaluate the addition of an entire second processing line, possibly a duplication of the first line, to process some of the approximately 0.3 billion tonnes of Measured & Indicated and 0.6 billion tonnes of Inferred sulphide resources not in reserves.

Santo Domingo Feasibility Study Update

The Company has continued updating the Feasibility Study ("FS") with contributions from international third parties, including Ausenco and Knight Piesold, and is progressing as planned towards releasing the updated FS in the first half of 2024. Santo Domingo is a fully permitted copper-iron-gold-cobalt project in the Atacama region of Chile, 35km northeast of Mantoverde. The updated FS will incorporate several improvements, including an updated mine plan with a lower strip ratio and modernized milling and flotation circuit with a lower overall footprint and operating cost compared with the previous design. The updated FS will also incorporate recently produced metallurgical testwork data and certain synergies in the Mantoverde - Santo Domingo district. One of the key improvements is the definition of an iron concentration circuit that can produce two different qualities of product: a bulk 65% grade iron concentrate and a premium 67% iron concentrate.

Mantoverde - Santo Domingo Cobalt Study

A district cobalt plant for Mantoverde - Santo Domingo may allow for low-cost by-product cobalt production while producing a by-product of sulphuric acid to be consumed internally to further significantly lower operating costs in the cathode process at Mantoverde.

The cobalt recovery process comprises a pyrite flotation step to recover cobaltiferous pyrite from MVDP tails and redirect it to the dynamic heap leach pads, which will be upgraded to a bio-leach configuration through the addition of an aeration system. The pyrite oxidizes in the leach pads and the solubilized cobalt is recovered via an ion exchange plant treating a bleed stream from the copper solvent extraction plant. The approach has been successfully demonstrated at the bench scale, and onsite piloting commenced in January 2024.

Engineering has commenced for a small plant treating only Mantoverde pyrite concentrates to produce up to 1,500 tonnes per annum ("tpa") of contained cobalt. In line with this, Santo Domingo has started a study to assess, as part of the copper/iron circuit overall layout optimization being conducted by Ausenco, the optimum process configuration for the pyrite flotation and pumping transportation facilities needed to transport pyrite concentrate to Mantoverde's leach facilities. This information will be part of the MV-SD cobalt study expected by the end of 2024.

At a combined MV-SD target of 4.5 to 6.0 thousand tpa of mined cobalt production, this would be one of the largest and lowest cost cobalt producers in the world, outside of Indonesia and the DRC.

PV District Growth Study

The company continues to review and evaluate the consolidation potential of the Pinto Valley district. Opportunities under evaluation include a potential mill expansion and increased leaching capacity supported by optimized water, heap and dump leach, and tailings infrastructure. District consolidation could unlock significant ESG opportunities and may transform our approach to create value for all stakeholders in the Globe-Miami District.

Management Additions

Effective February 20, 2024, David Taylor joined Capstone as Vice President, Health & Safety ("HSE"). Mr. Taylor brings with him 28 years of HSE experience in various sectors including mining, civil and mining infrastructure construction and engineering services and experience working in both Latin and North America. Over the course of his career, Mr. Taylor has worked at Stantec, Golder Associates, Stracon, Sierra Gorda SCM, and SNC Lavalin, amongst others.

Environmental, Social and Governance ("ESG") Highlights

At Mantos Blancos, 100% of the 2023 electricity use was covered by renewable electricity certified sources. The Company is working towards transitioning to 50% renewable electricity in Chile by 2025, and more than 90% renewable electricity across Capstone by 2030.

Mantoverde and Mantos Blancos received ISO 50001 Energy Efficiency Management System certification.

Greenhouse gas emissions and Energy Management teams were formed at all sites to lead the development of operating level greenhouse gas emissions and energy reduction plans.

Corporate Exploration Update

Cozamin: Infill drilling at Mala Noche Main Vein West Target was conducted in Q1 2024 utilizing one underground rig positioned at the level 19.1 cross-cut. The initial mineral resource estimate for this target is planned for May 2024.

Copper Cities, Arizona: On January 20, 2022, Capstone Mining announced that it had entered into an 18-month access agreement with BHP Copper Inc. ("BHP") to conduct drill and metallurgical test-work at BHP's Copper Cities project ("Copper Cities"), located approximately 10 km east of the Pinto Valley mine. An amendment to the agreement was completed in March 2023 extending the term by another six months. A second amendment to the agreement now extends the term further to September 2024. Drilling with two surface rigs twinning historical drill holes was completed in 2022 with metallurgical testing continuing in 2024. As explained in the PV District Growth Study section, district consolidation opportunities are being evaluated.

Mantoverde, Santo Domingo, and Mantos Blancos, Chile: Infill drilling was conducted during Q1 2024 in both Mantoverde and Mantos Blancos pits. District exploration activities included the completion of rock geochemistry and additional surface mapping program north of Mantoverde district to support additional targeting for near-mine and resource expansion opportunities.

The Company envisions commencing in H2 2024 an initial two-year $25 million exploration program at Mantoverde which is planned to include over 61,500 metres of drilling. This program aims to: i) target higher copper grades; ii) explore new areas adjacent or inside the current Mantoverde pits with the potential to add new reserves and/or resources; and iii) test high priority targets in the northern area of the Mantoverde land package with the potential to support the MV-SD District.

2024 Guidance

The Company reiterates its 2024 consolidated production, C1 cash costs¹, and capital expenditures (including capitalized stripping) guidance of 190-220kt of copper, $2.30 to $2.50 per payable pound and $455 million, respectively. The Company also reiterates the first half (H1) and second half (H2) production and cost guidance ranges announced on January 24, 2024. We expect production to be back-half weighted, with sequential quarter-over-quarter improvements in copper production, driven largely by the ramp-up at the Mantoverde Development Project.

MVDP remains on track and on budget, with first saleable concentrate expected in Q2 2024 and the achievement of nameplate operating rates expected during Q3 2024.

FINANCIAL OVERVIEW

Please refer to Capstone's Q1 2024 MD&A and Financial Statements for detailed financial results.

CONFERENCE CALL AND WEBCAST DETAILS

Capstone will host a conference call and webcast on Thursday, May 2 at 5:00 pm Eastern Time / 2:00 pm Pacific Time (Friday, May 3, 2024, 7:00 am Australian Eastern Standard Time). Link to the audio webcast: https://app.webinar.net/yE97V7pezQr

Dial-in numbers for the audio-only portion of the conference call are below. Due to an increase in call volume, please dial-in at least five minutes prior to the call to ensure placement into the conference line on time.

Toronto: 416-764-8650
Vancouver: 778-383-7413
Australia: 613-627-2402
North America toll free: 888-664-6383

A replay of the conference call will be available until May 9, 2024. Dial-in numbers for Toronto: (+1) 416-764-8677 and North American toll free: 888-390-0541. The replay code is 176405#. Following the replay, an audio file will be available on Capstone's website at https://capstonecopper.com/investors/events-and-presentations/.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

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 our expectations or beliefs regarding future events. Our Sustainable Development Strategy goals and strategies are based on a number of assumptions, including, but not limited to, the biodiversity and climate-change consequences; availability and effectiveness of technologies needed to achieve our sustainability goals and priorities; availability of land or other opportunities for conservation, rehabilitation or capacity building on commercially reasonable terms and our 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, our ability to successfully implement new technology; and the performance of new technologies in accordance with our expectations.

Forward-looking statements include, but are not limited to, statements with respect to the estimation of Mineral Resources and Mineral Reserves, the success of the underground paste backfill and tailings filtration projects at Cozamin, the timing and cost of the Mantoverde Development Project ("MVDP"), the timing and 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 timing and results of the Santo Domingo FS Update and success of incorporating synergies previously identified in the Mantoverde - Santo Domingo District Integration Plan, 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 our mining operations, the continuing success of mineral exploration, the estimations for potential quantities and grade of inferred resources and exploration targets, our ability to fund future exploration activities, our ability to finance the Santo Domingo project, environmental 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, our estimates of available liquidity, and the risks included in our continuous disclosure filings on SEDAR+ at www.sedarplus.ca. The impact of global events such as pandemics, geopolitical conflict, or other events, to Capstone is dependent on a number of factors outside of our 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 our 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, our ability to raise capital, Capstone Copper's ability to acquire properties for growth, counterparty risks associated with sales of our metals, use of financial derivative instruments and associated counterparty risks, foreign currency exchange rate fluctuations, market access restrictions or tariffs, changes in general economic conditions, availability and quality of water, 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, our ability to meet the requirements under the Cozamin Silver Stream Agreement with Wheaton Precious Metals Corp. ("Wheaton"), our 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 our 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 our workforce, risks related to construction activities at our operations and development projects, suppliers and other essential resources and what effect those impacts, if they occur, would have on our business, including our ability to access goods and supplies, the ability to transport our 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 project, risks related to the Mantoverde Development Project, increased operating and capital costs, increased cost of reclamation, challenges to title to our 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 our operations and communities in which we operate, dependence on key management personnel, potential conflicts of interest involving our directors and officers, corruption and bribery, limitations inherent in our 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, our ability to integrate new acquisitions and new technology into our 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 our actual results, performance or achievements to differ materially from those described in our forward-looking statements, there may be other factors that cause our results, performance or achievements not to be as anticipated, estimated or intended. There can be no assurance that our forward-looking statements will prove to be accurate, as our actual results, performance or achievements could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on our forward-looking statements.

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 compliant technical reports titled "NI 43-101 Technical Report on the Cozamin Mine, Zacatecas, Mexico" effective January 1, 2023, "NI 43-101 Technical Report on the Pinto Valley Mine, Arizona, USA" effective March 31, 2021, "Santo Domingo Project, Region III, Chile, NI 43-101 Technical Report" effective February 19, 2020, and "Mantos Blancos Mine NI 43-101 Technical Report Antofagasta / Región de Antofagasta, Chile" and "Mantoverde Mine and Mantoverde Development Project NI 43-101 Technical Report Chañaral / Región de Atacama, Chile", both effective November 29, 2021.

The disclosure of Scientific and Technical Information in this document was reviewed and approved by 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 project updates at Santo Domingo and Mineral Reserves and Resources at Mantos Blancos and Mantoverde) all Qualified Persons under NI 43-101.

Non-GAAP and Other Performance Measures

The Company uses certain performance measures in its analysis. These Non-GAAP performance measures are included in this document because these statistics are key performance measures that management uses to monitor performance, to assess how the Company is performing, and to plan and 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.

Some of these performance measures are presented in Highlights and discussed further in other sections of the document. These measures provide meaningful supplemental information regarding operating results because they exclude certain significant items that are not considered indicative of future financial trends either by nature or amount. As a result, these items are excluded for management assessment of operational performance and preparation of annual budgets. These significant items may include, but are not limited to, restructuring and asset impairment charges, individually significant gains and losses from sales of assets, share based compensation, unrealized gains or losses, and certain items outside the control of management. These items may not be non-recurring. However, excluding these items from GAAP or Non-GAAP results allows for a consistent understanding of the Company's consolidated financial performance when performing a multi-period assessment including assessing the likelihood of future results. Accordingly, these Non-GAAP financial measures may provide insight to investors and other external users of the Company's consolidated financial information.

C1 Cash Costs Per Payable Pound of Copper Produced

C1 cash costs per payable pound of copper produced is a measure reflective of operating costs per unit. C1 cash costs is calculated as cash production costs of metal produced net of by-product credits and is a key performance measure that management uses to monitor performance. Management uses this measure to assess how well the Company's producing mines are performing and to assess overall efficiency and effectiveness of the mining operations and assumes that realized by-product prices are consistent with those prevailing during the reporting period.

All-in Sustaining Costs Per Payable Pound of Copper Produced

All-in sustaining costs per payable pound of copper produced is an extension of the C1 cash costs measure discussed above and is also a non-GAAP key performance measure that management uses to monitor performance. Management uses this measure to analyze margins achieved on existing assets while sustaining and maintaining production at current levels. Consolidated All-in sustaining costs includes sustaining capital and corporate general and administrative costs.

Net debt / Net cash

Net debt / Net cash is a non-GAAP performance measure used by the Company to assess its financial position and is composed of Long-term debt (excluding deferred financing costs and purchase price accounting ("PPA") fair value adjustments), Cost overrun facility from MMC, Cash and cash equivalents, Short-term investments, and excluding shareholder loans.

Attributable Net debt / Net cash

Attributable net debt / net cash is a non-GAAP performance measure used by the Company to assess its financial position and is calculated as net debt / net cash excluding amounts attributable to non-controlling interests.

Available Liquidity

Available liquidity is a non-GAAP performance measure used by the Company to assess its financial position and is composed of RCF credit capacity, the $520 million Mantoverde DP facility capacity, Cash and cash equivalents and Short-term investments. For clarity, Available liquidity does not include the Mantoverde $60 million cost overrun facility from MMC nor the $260 million undrawn portion of the Gold stream from Wheaton related to the Santo Domingo project as they are not available for general purposes.

Adjusted net (loss) income attributable to shareholders

Adjusted net (loss) income attributable to shareholders is a non-GAAP measure of Net loss attributable to shareholders as reported, adjusted for certain types of transactions that in our judgment are not indicative of our normal operating activities or do not necessarily occur on a regular basis.

EBITDA

EBITDA is a non-GAAP measure of net loss before net finance expense, tax expense, and depletion and amortization.

Adjusted EBITDA

Adjusted EBITDA is non-GAAP measure of EBITDA before the pre-tax effect of the adjustments made to net loss (above) as well as certain other adjustments required under the RCF agreement in the determination of EBITDA for covenant calculation purposes.

The adjustments made to Adjusted net (loss) income attributable to shareholders and Adjusted EBITDA allow management and readers to analyze our results more clearly and understand the cash generating potential of the Company.

Sustaining Capital

Sustaining capital is expenditures to maintain existing operations and sustain production levels. A reconciliation of this non-GAAP measure to GAAP segment MPPE additions is included within the mine site sections of this document.

Expansionary Capital

Expansionary capital is expenditures to increase current or future production capacity, cash flow or earnings potential. A reconciliation of this non-GAAP measure to GAAP segment MPPE additions is included within the mine site sections of this document.

Realized copper price (per pound)

Realized price per pound is a non-GAAP ratio that is calculated using the non-GAAP measures of revenue on new shipments, revenue on prior shipments, and pricing and volume adjustments. Realized prices exclude the effects of the stream cash effects as well as TC/RCs. Management believes that measuring these prices enables investors to better understand performance based on the realized copper sales in the current and prior period.

View source version on businesswire.com: https://www.businesswire.com/news/home/20240502817397/en/

Jerrold Annett, SVP, Strategy and Capital Markets
647-273-7351
jannett@capstonecopper.com

Daniel Sampieri, Director, Investor Relations & Strategic Analysis
437-788-1767
dsampieri@capstonecopper.com