Alamos Gold Announces Island Gold District Expansion to 20,000 TPD, Creating One of Canada’s Largest and Lowest Cost Gold Mines with Attractive Economics, including 69% After-Tax IRR and $12.2 Billion NPV at $4,500/oz Gold

Press Release

TORONTO, Feb. 03, 2026 — Alamos Gold Inc. (TSX:AGI; NYSE:AGI) (“Alamos” or the “Company”) today reported results of the Expansion Study (“IGD Expansion”) completed on the Island Gold District operation, located in Ontario, Canada. Compared to the Base Case Life of Mine Plan (“Base Case LOM”) released in June 2025, the IGD Expansion incorporates a 30% increase in Mineral Reserves, and an expansion of the Magino mill to 20,000 tonnes per day (“tpd”) supporting increased processing rates of 3,000 tpd of high-grade underground ore, and 17,000 tpd from the open pit. This is expected to drive production higher and create one of the largest, longest life, and most profitable gold operations in Canada.

“The evolution and growth of Island Gold continues with another substantial increase in Mineral Reserves supporting another high-return expansion of the operation. The IGD Expansion is starting to unlock the true potential of the Island Gold District with the increase in mining rates expected to drive production to more than 530,000 ounces per year at among the lowest costs in the industry. The IGD Expansion has driven the value of the operation to over $12 billion at gold prices of $4,500 per ounce, up from a combined acquisition cost for Island Gold and Magino of $1.4 billion. Given our significant ongoing exploration success within the main Island Gold structure and spectacular high-grade results we are seeing within the nearby Cline-Pick targets, we are confident there is further growth and upside to come,” said John A. McCluskey, President and Chief Executive Officer.

IGD Expansion Study Highlights:

Increased production: average annual production of 534,000 ounces over 10 years post expansion (2028+), a 27% increase from the Base Case LOM, and 113% increase from 2025

• Average annual production of 490,000 ounces over 15 years during which both the open pit and underground are operating (based on Mineral Reserves only)

Low-cost structure: average mine-site AISC of $1,025 per ounce over the initial 10 years post expansion (2028+), a decrease of approximately 31% from 2025

• Average total cash costs of $682 per ounce over the initial 10 years (2028+), and $717 per ounce over 15 years with both the open pit and underground operating
• Average AISC of $1,032 per ounce over 15 years, similar to the Base Case LOM and representing an approximate 30% decrease from 2025

Larger, long-life operation underpinned by 30% increase in Mineral Reserves to 8.3 million ounces (128.2 million tonnes (“mt”) grading 2.01 grams per tonne (“g/t Au”), including:

• 5.1 million ounces grading 10.61 g/t Au (15.1 mt) at Island Gold underground, up 25% from the Base Case LOM
• 3.1 million ounces grading 0.86 g/t Au (113.1 mt) at Magino open pit, up 40% from the Base Case LOM
• 19-year mine life, similar to the Base Case LOM despite increasing underground and open pit mining and processing rates

Low capital intensity and total all-in cost per ounce providing significant margins and profitability

• Growth capital for the IGD Expansion of $542 million focused on the expansion of the Magino mill, and accelerated underground development and mobile equipment to support the higher underground and open pit mining rates
• Including remaining spending on the Phase 3+ Expansion, total growth capital of $704 million, the majority of which will be spent over the next three years
• Sustaining capital of $2,342 million, or $302 per ounce sold, consistent with the Base Case LOM. Total capital of $393 per ounce sold
• Total all-in cost, including growth capital, of $1,155 per ounce providing significant pre-tax margins of more than $3,500 per ounce at current gold prices

Attractive economics with significant upside

• After-tax net present value (“NPV”) (5%) of $8.2 billion, (long-term gold price assumption of $3,200 per ounce and USD/CAD foreign exchange rate of $0.74:1)
• After-tax internal rate of return (“IRR”) of 53%
• After-tax NPV (5%) of $12.2 billion and an after-tax IRR of 69% at a gold price of $4,500 per ounce

Significant upside potential through ongoing Mineral Reserve growth and incorporation of higher-grade regional targets

• Underground Mineral Reserves have increased for 13 consecutive years. With the deposit open laterally and at depth, there is excellent potential for this growth to continue
• Measured & Indicated Mineral Resources of 2.0 million ounces and Inferred Mineral Resources of 1.4 million ounces have not been incorporated into the IGD Expansion Study and represent upside through ongoing resource conversion
• Multiple regional targets, including the nearby past producing Cline-Pick mine, represent further production upside potential as opportunities for additional higher-grade mill feed within the expanded mill. The best hole drilled to date at the Cline-Pick target was announced in a press release earlier this week with grades averaging 178 g/t Au over 3.5 metres

Low and decreasing Greenhouse Gas (“GHG”) emission intensity

• 56% reduction of GHG emissions per ounce from levels already 30% lower than the industry average. This is expected to be achieved through the completion of the Phase 3+ Expansion, and connecting the Magino mill to grid power in late 2026

IGD Expansion largely de-risked and expected to be completed in 2028

• Phase 3+ Expansion remains on track for completion late in 2026, with the shaft and paste plant infrastructure designed to support higher underground mining rates of 3,000 tpd
• Construction of the larger mill is well underway and sized for 20,000 tpd such that key components of the IGD Expansion are largely de-risked

Growing free cash flow while funding growth

• Island Gold District is expected to self-finance all growth capital while generating growing free cash flow through to the completion of the expansion in 2028
• After-tax free cash flow is expected to increase to average $0.8 billion per year over 10 years (starting in 2028+) at a long-term gold price of $3,200 per ounce
• At a gold price of $4,500 per ounce, average after-tax free cash flow is expected to increase to $1.3 billion per year over 10 years (starting in 2028+)

Read More

IBF4