Fortuna intersects 7.8 g/t gold over 12.8 meters at Southern Arc, Diamba Sud, and advances exploration at Bambadji, Senegal

Fortuna Mining Corp. (FVI) reported additional exploration assay results from the Southern Arc and Kassasoko deposits at Diamba Sud in Senegal, alongside the commencement of drilling at Kabewest on its newly acquired Bambadji ground. The company completed 196 reverse circulation and diamond holes totaling 36,592 meters at Southern Arc since its February 2026 update, concluding that program. Additionally, 53 holes totaling 8,787 meters were drilled at Kassasoko. Management intends to release an updated Mineral Resource and Mineral Reserve estimate by year-end, with further step-out drilling planned for 2027.

At Bambadji, six rigs—five diamond drill rigs and one reverse circulation rig—are operating at Kabewest under an $8 million, 51,000-meter program for the remainder of 2026. Logging results indicate hydrothermal brecciation, hematite-silica alteration, and pyrite, though no assays have been reported. A maiden Inferred Resource for Kabewest is guided for release in the first quarter of 2027.

Reported intercepts, all widths described as estimated true width (ETW), include:

• Southern Arc: DSDD699 — 6.8 g/t Au over 12.0 m ETW from 96 m, including 18.9 g/t over 2.4 m from 98 m and 22.6 g/t over 0.8 m from 103 m
• Southern Arc: DSDD715 — 2.4 g/t over 28.0 m from 92 m, and 2.8 g/t over 20.8 m from 155 m, including 24.6 g/t over 0.8 m from 169 m
• Southern Arc: DSDD792 — 5.0 g/t over 7.2 m from 154 m; 3.9 g/t over 17.6 m from 186 m; 1.9 g/t over 13.6 m from 216 m
• Southern Arc: DSDD799 — 1.8 g/t over 56.8 m ETW from 26 m, including 24.5 g/t over 0.8 m from 85 m
• Southern Arc: DSR1149 — 1.4 g/t over 18.4 m from 187 m, and 3.9 g/t over 40.8 m ETW from 228 m, including 17.3 g/t over 1.6 m from 261 m
• Southern Arc: DSR1128 — 7.8 g/t over 12.8 m ETW from 103 m (the headline hole), including 59.5 g/t over 0.8 m from 112 m
• Southern Arc: DSR1132 — 4.5 g/t over 20.0 m ETW from 65 m, including 59.7 g/t over 0.8 m from 69 m
• Kassasoko: DSR1119 — 5.0 g/t over 5.6 m from 88 m; 2.9 g/t over 5.6 m from 131 m; 8.1 g/t over 5.6 m from 146 m
• Kassasoko: DSR1122 — 3.5 g/t over 11.2 m from 49 m; 8.8 g/t over 1.6 m from 137 m
• Kassasoko: DSR1157 — 2.8 g/t over 9.6 m from 75 m; 3.0 g/t over 27.2 m from 95 m; and a 3.2 m interval from 178 m (the release headline attributes 28.3 g/t to this interval; the Appendix table shows 3.3 g/t)
• Kassasoko: DSR1169 — 4.8 g/t over 11.2 m from 139 m
• Kassasoko: DSR1171 — 1.0 g/t over 16.8 m from 96 m; 1.9 g/t over 24.0 m from 160 m

Fortuna Mining Corp. (FVI) is a mid-tier producer operating three mines: Séguéla, Lindero, and Caylloma. The company has issued 2026 guidance for 281,000-305,000 GEO, with 214,754 GEO produced through the first nine months of 2026. Prior-period context, not disclosed in today’s release, includes Q2 2026 revenue of US$318.4 million, adjusted EBITDA of US$200.8 million at a 63% margin, and free cash flow from ongoing operations of US$85.7 million. The company holds US$606.7 million in cash against US$169.7 million in total debt, with total equity of US$1.819 billion, or US$6.15 per share. At a C$15.57 share price, the equity trades at roughly 1.6-1.8x book depending on the CAD/USD conversion, and the market capitalization is approximately C$4.6 billion on 295,957,387 shares outstanding.

The value event for the company is the year-end Mineral Resource and Mineral Reserve update, to which these drill holes are an input. For scale, Diamba Sud's entire Probable Reserve is 1.15 moz, carrying an after-tax NPV5% of US$1.0 billion at US$3,500/oz. Even a generous 10-15% lift in reserve ounces from these extensions might add on the order of US$50-100 million of NPV in the current gold tape — roughly 1.5-3% of the equity, before conversion risk and before the 2027 drilling that is still required.

The most recent significant Southern Arc results before today were published on 8 December 2025 (DSDD555 — 6.8 g/t over 35.5 m true width, about 241 g.m) and 25 February 2026 (headline 6.0 g/t over 24.1 m, about 145 g.m, alongside the 73% resource increase). Against that benchmark, today's best interval (159 g.m at 3.9 g/t over 40.8 m) is above the February anchor and below the December anchor, and today's headline hole (100 g.m) is below both. On grade, today's holes are lower grade but comparable on width. This represents a modest length gain at lower grade, rather than a degraded grade-and-width combination.

The stock closed at C$18.08 on 25 February 2026, the day the February anchor was published, and trades at C$15.57 today — 14% below that level and 16% below the C$18.64 52-week high. A stock that has round-tripped is not priced for the next hole to repeat the last one; the drilling is not what is driving this equity. The gold tape and the growth pipeline, including the Diamba Sud FS, Séguéla expansion, and the US$200 million Bambadji acquisition, are the primary drivers.

This release lands six days after a soft Q3 2026 production print of 69,665 GEO, down from 72,217 in Q2 and 72,462 in Q3 2025, due to a contractor equipment-availability problem and an artisanal-miner blockade at Séguéla. The shares fell from C$15.90 to C$14.44 around that release and have recovered to C$15.57.

Fortuna Mining Corp., a Vancouver-headquartered precious metals producer listed on the NYSE (FSM) and TSX (FVI) and reporting in US dollars, operates mines in Côte d'Ivoire, Argentina, and Peru. Its Séguéla mine in Côte d'Ivoire was the largest contributor, producing 33,744 oz Au in Q3 2026. The Lindero mine in Argentina, a heap-leach operation with a grade around 0.63 g/t, produced 26,024 oz Au in Q3 2026. The Caylloma mine in Peru, a silver-lead-zinc operation, produced 247,367 oz Ag, 11.4 Mlb Zn, and 8.4 Mlb Pb in Q3 2026.

The company is advancing the Diamba Sud project in Senegal, for which a Feasibility Study was delivered in June 2026. The project contains 20.5 Mt at 1.75 g/t Au and 1.15 moz Probable Reserves, with a 9.4-year life. It is projected to produce an average of 116 koz/yr, including 158 koz/yr over the first four years. At US$3,500/oz, the project has an after-tax NPV5% of US$1.0 billion and an IRR of 60%, with an initial capital requirement of US$397.5 million. First gold is targeted for Q2 2028, with a Final Investment Decision (FID) expected in Q4 2026.

Exploration activities include Diamba Sud and Bambadji in Senegal. The Bambadji asset was acquired from Barrick and IAMGOLD in August 2026 for US$200 million cash plus a 0.5% NSR on the first 1.75 moz from Bambadji Nord. Additional exploration is underway at Sunbird underground and brownfields at Séguéla, Lindero brownfields, plus Guinea and the Quartzstone earn-in in Guyana.

According to prior-period context from the provided Q2 2026 statements and MD&A, Fortuna held cash of US$606.7 million and total debt of US$169.7 million, resulting in net cash of approximately US$434 million. The company had a US$150 million undrawn credit facility and a book value of US$6.15 per share. In H1 2026, the company executed US$106.6 million of buybacks, including 8.6 million shares in Q2 alone. Shares outstanding fell from 305,760,679 at end-2025 to 295,957,387 at 30 June 2026. The company’s growth target is approximately 500,000 oz/yr of gold equivalent by 2028, funded from operating cash flow and existing liquidity.