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

2026-02-04

TSX - Toronto Stock Exchange · Gold · Canada

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

All amounts are in United States dollars, unless otherwise stated

TORONTO, Feb. 03, 2026 (GLOBE NEWSWIRE) -- 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 ounceproviding 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 potentialas 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+)

| IGD Expansion Study Highlights | | | | Production | Base Case LOM6 (June 2025) | Expansion Study6 (Feb 2026) | | Mine life (years) | 19 | 19 | | Project completion date – Phase 3+ Expansion | Q4 2026 | | | Project completion date – IGD Expansion to 20,000 tpd | | Q1 2028 | | | | | | Total gold production (000 ounces) | 5,836 | 7,963 | | Average annual gold production – 10-year average, 2028+ (000 ounces) | 419 | 534 | | Average annual gold production – 15-year average, 2026-2040 (000 ounces) | 365 | 490 | | | | | | Total mill feed (000 tonnes) | 84,838 | 128,210 | | Average mill throughput – 2028+ (tpd) | 12,400 | 20,000 | | Average gold grade (g/t Au) | 2.22 | 2.01 | | Average Island Gold ore throughput – 2029+ (tpd) | 2,400 | 3,000 | | Average Island Gold ore grade milled (g/t Au) | 10.81 | 10.61 | | Average Magino ore throughput – 2028+ (tpd) | 10,000 | 17,000 | | Average Magino ore grade milled (g/t Au) | 0.92 | 0.86 | | Average recovery (%) | 96.2% | 96.2% | | Operating Costs | | | | Open pit mining cost (C$/tonne of total material mined) | $4.14 | $4.85 | | Underground mining cost (C$/tonne of ore mined) | $122 | $135 | | Processing cost (C$/tonne of ore milled) | $16.38 | $18.13 | | G&A cost (C$/tonne of ore milled) | $13.43 | $12.41 | | Total cash cost – 10-year average, 2028+ (per ounce sold)1,2 | $577 | $682 | | Total cash cost – 15-year average, 2026-2040 (per ounce sold)1,2 | $628 | $717 | | Mine-site all-in sustaining cost – 10-year average, 2028+ (per ounce sold)1,2 | $897 | $1,025 | | Mine-site all-in sustaining cost – 15-year average, 2026-2040 (per ounce sold)1,2 | $937 | $1,032 | | Capital Costs (millions) | | | | Growth capital expenditure – Base Case LOM (including Phase 3+) | $151 | $162 | | Growth capital expenditure – IGD Expansion | - | $542 | | Total growth capital expenditure | $151 | $704 | | Sustaining capital expenditure5 | $1,693 | $2,342 | | Total capital expenditure – life of mine | $1,844 | $3,046 | | Total capital expenditure (per ounce sold) – life of mine2 | $324 | $393 | | Total all-in cost (per ounce sold) – life of mine2,3 | $1,009 | $1,155 | | Economic Analysis: $3,200/oz Gold Price (USD/CAD foreign exchange rate of $0.74:1)4 | | | | IRR (after-tax)7 | - | 53% | | NPV @ 0% discount rate (millions, after-tax) | $9,840 | $11,851 | | NPV @ 5% discount rate (millions, after-tax) | $7,187 | $8,160 | | Economic Analysis at $4,500/oz Gold Price (USD/CAD foreign exchange rate of $0.74:1) | | | | IRR (after-tax)7 | - | 69% | | NPV @ 0% discount rate (millions, after-tax) | $14,195 | $18,024 | | NPV @ 5% discount rate (millions, after-tax) | $10,184 | $12,239 |

1. Total cash costs and mine-site all-in sustaining costs include royalties and silver as a by-product credit 2. Please refer to the Cautionary Notes on non-GAAP Measures and Additional GAAP Measures 3. Total all-in cost per ounce sold is calculated as total cash cost per ounce plus total capital per ounce sold over the life of mine 4. IGD Expansion and Base Case LOM Plan include a gold price of $4,000/oz in 2026 and 2027, $3,800/oz in 2028, $3,600/oz in 2029 and a long-term (2030+) gold price of $3,200/oz, as well as a USD/CAD foreign exchange rate of $0.74:1 5. Sustaining capital includes reclamation and capital leases 6. Base Case LOM and IGD Expansion summary and economics from 2026 onwards, using the same gold price and USD/CAD foreign exchange rate assumptions 7. IRR is calculated on the differential after-tax cash flow between the IGD Expansion and running the operation at 12,400 tpd over the life of mine

Mineral Reserves and Resources

A larger Proven and Probable Mineral Reserve totaling 8.3 million ounces grading 2.01 g/t Au (128.2 million tonnes (“mt”)) has been included in the IGD Expansion Study. This represents a 30% increase from the 6.3 million ounces contained in the Base Case LOM. The increase was driven by a successful delineation drilling program completed at both the Island Gold underground and Magino open pit deposits with the focus on converting a large portion of Mineral Resource base into Mineral Reserves.

Underground Mineral Reserves increased 25% from the Base Case LOM to 5.1 million ounces at similar grades of 10.61 g/t Au (15.1 mt). Open pit Mineral Reserves also increased 40% to 3.1 million ounces, at slightly lower grades of 0.86 g/t Au. Consistent with the approach for the Base Case LOM, only Mineral Reserves were incorporated into the IGD Expansion life of mine plan and economic analysis.

Mineral Reserves – Effective as of December 31, 2025

| Tonnes | Grade | Ounces | Tonnes | Grade | Ounces | Tonnes | Grade | Ounces | | (000’s) | (g/t Au) | (000’s) | (000’s) | (g/t Au) | (000’s) | (000’s) | (g/t Au) | (000’s) | | | Island Gold | | | | | | | | | | | Proven | 1,123 | 11.50 | 415 | 821 | 11.82 | 312 | 37% | -3% | 33% | | Probable | 13,949 | 10.54 | 4,726 | 10,947 | 10.78 | 3,795 | 27% | -2% | 25% | | Proven and Probable | 15,072 | 10.61 | 5,141 | 11,769 | 10.85 | 4,107 | 28% | -2% | 25% | | Magino | | | | | | | | | | | Proven | 42,437 | 0.80 | 1,097 | 22,163 | 0.88 | 626 | 91% | -9% | 75% | | Probable | 70,704 | 0.90 | 2,044 | 54,710 | 0.92 | 1,613 | 29% | -2% | 27% | | Proven and Probable | 113,141 | 0.86 | 3,141 | 76,873 | 0.91 | 2,240 | 47% | -5% | 40% | | Island Gold District | | | | | | | | | | | Proven | 43,559 | 1.08 | 1,512 | 22,984 | 1.27 | 938 | 90% | -15% | 61% | | Probable | 84,653 | 2.49 | 6,769 | 65,657 | 2.56 | 5,408 | 29% | -3% | 25% | | Proven and Probable | 128,212 | 2.01 | 8,282 | 88,642 | 2.23 | 6,347 | 45% | -10% | 30% |

Mineral Reserves reported are consistent with the CIM Definition Standards for Mineral Resources and Mineral Reserves Mineral Reserves are reported to a cut-off grade of 3.78 Au g/t at Island Gold and 0.30 Au g/t for Magino The cut-off grades are based on a gold price of $1,800/oz Au at both Island Gold and Magino Silver is not used in the cut-off grade calculation Totals may not add up due to rounding Francis McCann, P.Eng, Director - Technical Services is the Qualified Person for Magino’s Mineral Reserve estimate. Mr. McCann is a Qualified Person within the meaning of Canadian Securities Administrator's National Instrument 43-101 ("NI 43-101") Nathan Bourgeault, P.Eng., Manager, Technical Services for the Island Gold District is the Qualified Person for Island Gold’s Mineral Reserve estimate. Mr. Bourgeault is a Qualified Person within the meaning of Canadian Securities Administrator's National Instrument 43-101 ("NI 43-101")

Mineral Resources for Island Gold underground and the Magino open pit were not included in the IGD Expansion mine plan and represent a significant upside opportunity to the IGD Expansion Study. With the Mineral Resource conversion rate at Island Gold underground continuing to average over 90%, a significant portion of the existing Mineral Resources are expected to convert to Mineral Reserves with further drilling.

Mineral Resources – Effective as of December 31, 2025

| Tonnes | Grade | Ounces | Tonnes | Grade | Ounces | Tonnes | Grade | Ounces | | | (000’s) | (g/t Au) | (000’s) | (000’s) | (g/t Au) | (000’s) | (000’s) | (g/t Au) | (000’s) | | | | Island Gold | | | | | | | | | | | | Measured | 329 | 11.19 | 118 | 470 | 14.66 | 222 | -30% | -24% | -47% | | | Indicated | 1,764 | 8.32 | 472 | 2,640 | 9.75 | 827 | -33% | -15% | -43% | | | Measured and Indicated | 2,093 | 8.77 | 590 | 3,110 | 10.49 | 1,049 | -33% | -16% | -44% | | | Magino | | | | | | | | | | | | Measured | 6,714 | 0.70 | 151 | 5,061 | 0.87 | 141 | 33% | -20% | 7% | | | Indicated | 50,084 | 0.80 | 1,288 | 55,209 | 0.91 | 1,615 | -9% | -12% | -20% | | | Measured and Indicated | 56,798 | 0.79 | 1,439 | 60,270 | 0.91 | 1,756 | -6% | -13% | -18% | | | Island Gold District | | | | | | | | | | | | Measured | 7,042 | 1.19 | 270 | 5,531 | 2.04 | 363 | 27% | -42% | -26% | | | Indicated | 51,848 | 1.056 | 1,760 | 57,849 | 1.31 | 2442 | -10% | -19% | -28% | | | Measured and indicated | 58,891 | 1.07 | 2,029 | 63,380 | 1.38 | 2,805 | -7% | -22% | -28% | | | Inferred Gold Mineral Resources (exclusive of Mineral Reserves) | | | | | | | | | | | | Island Gold | 2,867 | 11.51 | 1,061 | 2,449 | 16.88 | 1,329 | 17% | -32% | -20% | | | Magino | 14,045 | 0.75 | 338 | 40,291 | 0.92 | 1,191 | -65% | -18% | -72% | | | Island Gold District | 16,912 | 2.57 | 1,398 | 42,740 | 1.83 | 2,520 | -60% | 40% | -45% | |

Mineral Resources reported are consistent with the CIM Definition Standards for Mineral Resources and Mineral Reserves Mineral Resources are reported at an assumed gold price of $2,000/oz Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources estimated will be converted into Mineral Reserves Island Gold underground Resources are estimated at a cut-off grade of 3.36 g/t Magino open pit Resources are estimated at a cut-off grade of 0.28 g/t Au Contained Au ounces are in-situ and do not include metallurgical recovery losses Mineral Resources are exclusive of Mineral Reserves Totals may not add up due to rounding Jeffrey Volk, CPG, FAusIMM, Director of Reserves and Resources for Alamos Gold Inc is the Qualified Person for the Magino open pit Mineral Resource estimate. Tyler Poulin, P. Geo., Geology Superintendent for Alamos Gold , is the Qualified Person for the Island Gold underground Mineral Resource estimate. Mr. Volk and Mr. Poulin are Qualified Persons within the meaning of Canadian Securities Administrator's National Instrument 43-101 ("NI 43-101")

Economic Analysis

The IGD Expansion Study has an estimated after-tax NPV (5%) of $8.2 billion assuming a long-term gold price of $3,200 per ounce and USD/CAD foreign exchange rate of $0.74:1.

At a $4,500 per ounce gold price, the after-tax NPV (5%) increases to $12.2 billion. The mine plan, operating parameters and capital estimates incorporated in the IGD Expansion Study are based on costing as of the fourth quarter 2025 and do not include inflation. The project economics are sensitive to metal price assumptions and input costs as detailed in the tables below.

IGD Expansion After-Tax NPV (5%) Sensitivity ($ Millions)

| | -10% | -5% | Base Case | 5% | 10% | | Gold Price | $6,925 | $7,543 | $8,160 | $8,778 | $9,395 | | Canadian Dollar | $8,579 | $8,370 | $8,160 | $7,951 | $7,741 | | Capital Costs | $8,258 | $8,209 | $8,160 | $8,111 | $8,062 | | Operating Costs | $8,502 | $8,331 | $8,160 | $7,989 | $7,818 |

IGD Expansion After-Tax NPV (5%) Sensitivity to Gold Price1,2

| Gold Price ($/oz) | After-Tax NPV (5%) ($M) | After-Tax IRR (%) | | $2,800 | $6,046 | 43% | | $3,200 (Base Case1) | $8,160 | 53% | | $3,600 | $8,962 | 56% | | $4,000 | $10,419 | 62% | | $4,500 | $12,239 | 69% | | $5,000 | $14,060 | 75% | | $5,500 | $15,880 | 81% |

1. Base case includes a gold price of $4,000/oz in 2026 and 2027, $3,800/oz in 2028, $3,600/oz in 2029 and a long-term (2030+) gold price of $3,200/oz, as well as a USD/CAD foreign exchange rate of $0.74:1 2. IRR is calculated on the differential after-tax cash flow between the IGD Expansion and running the operation at 12,400 tpd over the life of mine

IGD Expansion Overview

The Island Gold District is comprised of the Island Gold underground mine and the Magino open pit mine. The IGD Expansion incorporates a 30% larger Mineral Reserve of 8.2 million ounces, and includes an expansion of the Magino mill to 20,000 tpd, as well as increased underground and open pit mining and processing rates. Relative to the Base Case LOM, underground mining and processing rates will increase by a further 25% to 3,000 tpd, and open pit processing rates will increase 70% to 17,000 tpd.

The mill expansion will include the construction of a parallel circuit with a capacity of 10,000 tpd, doubling the overall capacity of the mill. The new circuit is designed to process a blend of high-grade underground ore and open pit ore, with the existing circuit to be fed with open pit ore only.

The Island Gold mill will continue operating in 2026 and 2027 and will be dedicated to processing approximately 1,265 tpd of higher grade underground ore until the expected completion of the mill expansion in the first quarter of 2028. The remaining underground ore mined will be blended at increasing rates with open pit ore, and processed within the Magino mill. Following the completion of the IGD Expansion in 2028, the Island Gold mill will be shut down and all underground and open pit ore will be processed through the larger, centralized and more cost-effective Magino mill.

As part of the IGD Expansion, a number of improvements will be made to the existing Magino mill circuit. These include the addition of ore bins, a new truck dump configuration to allow for direct tipping of ore, and a centralized gyratory crusher that will provide more than 20,000 tpd of front-end crushing capacity. In addition to the connection of the mill to electric grid power, these changes will significantly improve the performance of the circuit by reducing ore rehandling, ensuring more consistent and higher ore flow into the mill, which will all contribute to lower processing costs.

Underground mining rates are expected to ramp up through 2026 from 1,400 tpd to 2,000 tpd by the end of the year. Following the expected completion of the Phase 3+ Expansion in the fourth quarter of 2026, underground mining will transition from trucking ore and waste to skipping ore and waste to surface through the new shaft infrastructure. This is expected to drive an increase in underground mining rates to 2,400 tpd in 2027. As part of the IGD Expansion, a further increase in underground mining rates to 3,000 tpd is expected by 2029, with the shaft and related infrastructure designed to support the higher mining rates. This will be processed through the expanded 20,000 tpd mill with the remaining 17,000 tpd coming from the open pit. To support the increase processing rates, open pit mining rates will also increase to average 80,000 tpd of total material and 17,000 tpd of ore. The increase in mining rates and expansion of the mill are expected to drive significant production growth over the next five years, at substantially lower costs.