In May 2025, TriStar announced the results of an updated prefeasibility study for Castelo de Sonhos. The updated study incorporated updates to the cost estimates, gold prices and exchange rates while the project scope, resources and reserves remain unchanged from the 2021 PFS.

The Updated PFS was completed by GE21 Consultoria Mineral Ltda ("GE21") of Belo Horizonte, Brazil, independent of the Company. For details, please see press release dated May 5, 2025, titled ‘TriStar Gold Updates Economics of PFS with After-Tax 40% IRR and US$603 Million NPV5 and Provides Update on Permit’ filed at www.sedarplus.ca.

Key Economic Parameters

The updated prefeasibility results suggest an after-tax NPV_5% of US$1,353 million at approx. spot of US$3,200 gold (May 2025) and an after-tax NPV_5% of US$603 million at US$2,200 base-case gold. After-tax IRR is estimated at 72% at US$3,200 gold and at 40% with the US$2,200 base case gold price.

These economics are based on the updated foreign exchange rate of US$1 = BRL5.75. The economics include the effect of the project royalties, including NSR royalties totaling 3.5% and Brazilian federal gross royalty of 1.5%.

Notes: Estimated All In Sustaining Costs per ounce of gold produced is a Non-GAAP measure that is equal the total of site mining costs, site and corporate G&A costs, royalties and production taxes, realized gains/losses on hedging transactions, community and permitting costs relating to current operations, refining costs, site based non-cash remuneration, inventory write-downs, stripping costs, byproduct credits, reclamation costs, and sustaining costs related to exploration and studies, capital exploration, capitalized stripping and underground mine development, and capital expenditures, divided by the estimated total ounces of gold produced during the life of the mine.

Annual Gold Production and AISC over life-of-mine:

Economic Sensitivities

The figures and tables below show the sensitivity of after-tax NPV and IRR to changes in the US dollar gold price.