Perpetua Resources : Investor Presentation October 2025

Perpetua Resources

Responsible Mining. Critical Resources.

Clean Future.

Investor Presentation - October 2025

NASDAQ: PPTA

TSX: PPTA

CAUTIONARY NOTE & TECHNICAL DISCLOSURE

The presentation has been prepared by Perpetua Resources management and does not represent a recommendation to buy or sell these securities. Investors should always consult their investment advisors prior to making any investment decisions. All references to "dollars" or "$" shall mean United States dollars unless otherwise specified.

The material scientific and technical information in respect of the Stibnite Gold Project in this presentation, unless otherwise indicated, is based upon information contained in the technical report titled "Stibnite Gold Project, Feasibility Study Technical Report, Valley County, Idaho" dated effective December 22, 2020, and issued January 27, 2021 (the "FS" or "2020 Feasibility Study"). The 2020 Feasibility Study was prepared in accordance with 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. These standards differ from the mining property disclosure rules specified in Subpart 1300 of Regulation S-K under the United States Securities Act of 1933 ("Subpart 1300") promulgated by the SEC. Accordingly, information concerning mineral deposits from the 2020 Feasibility Study set forth herein may not be comparable with information made public by companies that report in accordance with U.S. standards.

The Company has issued a Technical Report Summary (the "TRS"), dated as of December 31, 2021, and amended as of June 6, 2022, developed for the Stibnite Gold Project in accordance with the mining property disclosure rules specified in Subpart 1300 promulgated by the SEC. The TRS summarizes, in accordance with the mining property disclosure rules specified in Subpart 1300, the FS, which was completed under NI 43-101, with the following notable differences between the FS and the TRS:

• The TRS Mineral Resource estimates were developed based on a gold price of $1,500/oz versus the $1,250/oz gold price assumed for the FS. The change in gold price results from higher trailing average gold prices at the date of preparation for the respective reports.

• The Measured Mineral Resources in the FS were reclassified to Indicated Mineral Resources in the TRS due to differences in Subpart 1300 versus NI 43-101 Mineral Resources classification guidelines.

• The Proven Mineral Reserves from the FS were reclassified as Probable Mineral Reserves for the TRS resulting from the reclassification of the Measured Mineral Resources to Indicated Mineral Resources due to differences in Subpart 1300 versus NI 43-101 Mineral Resources classification guidelines.

• The TRS is classified as a Preliminary Feasibility level study whereas the FS was classified as a Feasibility level study. This change was driven by the Subpart 1300 requirement that a compliant Feasibility level TRS include a capital cost contingency allowance no greater than 10%, whereas the initial capital cost estimate for the FS included a more conservative allowance at approximately 15%.

All other technical analyses, design information, capital and operating cost information, economic analyses, permitting and legal assumptions, conclusions and recommendations are consistent between the TRS and the FS.

Financial data in the FS and TRS are based on cost estimates as of December 31, 2020, as set forth in the FS . On February 13, 2025, the Company released an updated cash flow model for the Project (the "Financial Update"). The Financial Update was prepared by the Company and is based, in part, on the basic engineering work completed by Ausenco Engineering USA South Inc. ("Ausenco") in January 2025, and with contributions from other mining engineers and consultants, utilities and financial advisors. It is intended to be read as a supplemental financial update to the cash flow forecast included in the FS with respect to economic information regarding the Project. Using the scientific and technical information presented in the FS, the Financial Update reflects the progression of the Project plan to a Basic Engineering level, including applying fourth quarter 2024 cost estimates for construction and operations and current and consensus commodity pricing for sales. Neither the Financial Update nor the studies or data underlying such update modifies the Mineral Resources and Mineral Reserves reported in the FS and the TRS or the material assumptions and information pertaining to such disclosure. The information contained in the Financial Update is subject to the assumptions, exclusions and qualifications set forth in the Company's Current Report on Form 8-K filed with the SEC on February 13, 2025 and included in the Company's Annual Report on Form 10-K filed with the SEC on March 19, 2025, as well as those contained in the FS and the TRS, except to the extent explicitly updated by the Financial Update.

Readers are encouraged to read the Financial Update and the Company's Current Report on Form 8-K filed with the SEC on February 13, 2025, which is available under the Company's profile on EDGAR. Readers are encouraged to read the TRS and the Company's Current Report on Form 8-K filed with the SEC on January 3, 2021, as amended by the Company's Current Report on Form 8-K/A filed with the SEC on June 8, 2022, which are available under the Company's profile on EDGAR. Readers are also encouraged to read the FS, which is available on the Company's website and under the Company's profile on SEDAR, for detailed information concerning the Project. The FS, the TRS and the Financial Update are intended to be read as a whole, and sections should not be read or relied upon out of context. References to the "Technical Reports" in this presentation refer to the FS, the TRS and the Financial Update, as applicable. See also "Regulatory Information" at the end of this presentation.

This presentation contains certain mineral reserve, production, costs, valuation, capitalization, trading data and similar information regarding certain other mineral projects and peer companies. Such data was derived from publicly available reports by such companies and other trade and industry sources. While the company believes such sources to be reliable, the company has not independently verified such information. Furthermore, information regarding mineral reserves, production and similar mineral project information for each company is based on estimates, assumptions and reporting standards applied to available data by each company and their reserve engineers in their respective reports, which may differ materially from the estimates, assumptions and reporting standards applied by us, and therefore may not be comparable among the companies presented. As a result, comparisons of such data made in this presentation, while considered reasonable at the time they are made, are subject to a variety of risks and uncertainties which could cause actual events or results of each company to differ materially from those reflected and there can be no assurance that we will be able to achieve similar results at similar stages of development.

Investors should be aware that the Letter of Interest from US EXIM is non-binding and conditional, and does not represent a financing commitment. A funding commitment, if any, is conditional upon successfully completing the due diligence and underwriting process, which may not be completed on the expected timeline, or at all, and receiving all required Project approvals. If the Company's application is approved, there can be no assurance that the EXIM financing will be for the full amount indicated in the LOI or the increased amount requested in the application, or that the approved EXIM financing will be sufficient for the Company to commence construction of the Project. Further, release of funding under any such commitment would be subject to the satisfaction of certain conditions and covenants by the Company.

Investors should be aware that the Company has not entered into any definitive agreement with respect to a royalty, streaming or guarantee and may not be able to enter into such agreement on the anticipated terms and timeline, or at all. In addition, the outcomes from such agreement, when entered into, may not be sufficient to satisfy the aggregate obligations of the Company to provide construction phase financial assurance under applicable federal and state law prior to commencing construction. Securing the financial assurance does not guarantee the Company will receive the USFS notice to proceed under the approved plan of operation and consummating the royalty or streaming financing may not satisfy the financial assurance conditions of various federal and state permits required to commence construction.

Investors should be aware that there can be no assurance that the that exploration activities will result in the discovery of additional resources or reserves. Exploration results are inherently uncertain and subject to numerous risks and uncertainties, including geological factors, market conditions, and regulatory changes. Furthermore, development of any additional resources and reserves discovered would be subject to any applicable NEPA and permitting requirements.

Investors should be aware that the Project's inclusion as a Transparency Project on the Permitting Dashboard does not imply endorsement of or support for the project by the federal government, or create a presumption that the Project will be approved, favorably reviewed by any agency, or receive federal funding. The inclusion of a project on the Permitting Dashboard may be reconsidered based on updated information. Additionally, investors should be aware that the Executive Order does not indicate any commitments on part of the

government or any government agency with regard to the applicability of any programs to the Project, or the timing or outcome of any such initiative that may be applicable to the Project. 3

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THE STIBNITE GOLD PROJECT

Our goal is to transform an area abandoned after 100 years of mining activity into a national strategic asset for critical mineral and gold production through responsible mining and a sustainable approach to restore the environment for the benefit of all stakeholders.

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RESTORING AN ABANDONED BROWNFIELDS SITE

ENVIRONMENTAL SOLUTIONS FUNDED THROUGH MINE DEVELOPMENT

SEDIMENTATION

Early repair of the largest source of sedimentation

METAL LEACHING

Pick up, reprocess, reuse and safely store 10.5M tons of tailings and spent ore

BLOCKED FISH MIGRATION

Re-establish fish migration and provide temporary and permanent river restoration

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