Fortuna reports 15% increase in mineral reserves driven by Séguéla expansion

Fortuna Mining (NYSE:FSM) has announced a significant expansion of its resource base, reporting a 15% year-over-year increase in consolidated Proven and Probable Mineral Reserves.

As of March 31, 2026, the company’s total reserves reached 3 million gold equivalent ounces (GEOs), a figure achieved even after accounting for 378,000 GEOs in annual production depletion across its global portfolio.

The growth was primarily driven by the Séguéla mine in Côte d’Ivoire, where successful infill and exploration drilling upgraded 819,000 GEOs from resources to reserves.

The Sunbird deposit at Séguéla saw its underground reserves rise 34% to 539,000 ounces (averaging 3.80 g/t Au), while its Inferred resources surged 55% to 417,000 ounces.

This expansion supports Fortuna's strategy of extending the mine life at Séguéla beyond 10 years.

Across the group, Measured and Indicated resources (excluding reserves) increased 56% to 2.1 million GEOs.

A major contributor to this jump was the Diamba Sud project in Senegal, which saw a 165% increase in its resource category.

The feasibility study for Diamba Sud remains on track for completion by the end of the second quarter of 2026, which will provide the maiden reserves necessary to support a formal construction decision.