Sunstone Metals (STM) investor relations material

Portfolio and strategy

• Two Ecuadorian gold-copper projects are positioned as potential large, long-life, low-cost assets, with gold and copper viewed as complementary commodities.

• Bramaderos is in southern Ecuador; El Palmar is in the north, along the copper-rich Toachi Fault and within a district containing major porphyry deposits.

• Ecuador’s USD currency, hydro-powered grid, and lower energy and labour costs are presented as potential cost advantages; Bramaderos has a 1.4:1 mining strip ratio.

Bramaderos

• October 2026 JORC Mineral Resource grew 72% to 6.2Moz AuEq, including 3.3Moz Indicated; the resource area spans 2km by 1.8km, with mineralisation reported from surface in 2026 drilling.

• The project-wide Exploration Target is 4.4–11.2Moz AuEq in addition to the resource: 3.5–9.5Moz from porphyry targets and 0.9–1.7Moz at Limon.

• Copete–Porotillo discovery contributed 1.3Moz AuEq to the resource; further drilling between Melonal and Copete is expected to test potential for a larger continuous open pit.

• April 2026 Scoping Study outlined multi-decade open-pit potential and a 1.4:1 strip ratio; subsequent metallurgical work lifted gold recovery from 85% to >93% and copper from 75% to >80%.

• Bramaderos is 87.5%-owned, with SolGold Canada holding 12.5% under a loan carried through to commercial production.

El Palmar

• Initial JORC Mineral Resource is 1.2Moz AuEq from 64Mt at 0.60g/t AuEq; the resource is near surface and described as a potential starter-pit opportunity.

• A 15–45Moz AuEq Exploration Target is additional to the resource, based on 1.0–1.2Bt grading 0.3–0.7g/t gold and 0.1–0.3% copper.

• T2 and T3 targets extend below 1,750m; drilling totals 17,699m, with deeper porphyry targets and copper potential supporting further exploration.

• The project is 74.5%-held, with a staged acquisition agreement offering a path to 100%; a separate agreement covers nearby Verde Chico.