Aston Bay Announces Pre-Feasibility Study Results and Maiden Mineral Reserve for the Storm Copper Project, Nunavut

TORONTO, ON / ACCESS Newswire / November 10, 2026 / Aston Bay Holdings Ltd. (TSXV:BAY)(OTCQB:ATBHF) ("Aston Bay" or the "Company") is pleased to announce the results of the Pre-Feasibility Study ("PFS") for the Storm Copper Project ("Storm" or the "Project") on Somerset Island, Nunavut, Canada. The Project is held in a joint venture with American West Metals Limited ("American West"), which holds an 80% interest and is the operator, with Aston Bay maintaining a free carried interest until a decision to mine is made upon completion of a bankable feasibility study. The PFS was prepared by Sacré-Davey Engineering Inc. ("Sacré-Davey") with specialist contributors and supports the first Mineral Reserve Estimate for the Project.

The PFS evaluates a contractor-operated, open-pit mine at the Cyclone, Chinook, Corona and Thunder Deposits. Ore is planned to be upgraded on site by sensor-based sorting and gravity concentration, with flotation of the fine fraction, to produce a copper-silver concentrate that is shipped during the summer open-water season. Mining is scheduled over approximately 8.6 years, from January 2030 to July 2038. Processing runs from April 2030 to April 2040 and treats stockpiled lower-grade ore after mining ends. The last concentrate shipment is in September 2040, for a production life of 10.5 years.

The production plan and economic analysis are based only on Probable Mineral Reserves. Inferred Mineral Resources are treated as waste and contribute no tonnes, metal or revenue to the PFS case.

All amounts are in Canadian dollars (C$) unless otherwise stated. Metal prices, concentrate commercial terms and cash costs per pound of copper are in US dollars (US$). Conversions between currencies use an exchange rate of C$1.39 per US$1.00 (US$0.72 per C$1.00). NPV is reported in both C$ and US$. IRR and payback are reported once, as they are the same in either currency at a constant exchange rate. All figures are on a 100% Project basis, before allocation between the joint venture participants. Costs and prices are in real terms, without escalation. Unless stated otherwise, results are for the base case.

Cautionary Note

The PFS is based on Probable Mineral Reserves only; no Inferred Mineral Resources are included in the mine plan or economic analysis. The capital and operating cost estimates are AACE Class 4 estimates with an accuracy range of −30% to +50%. The PFS is not a Feasibility Study and no decision to develop the Project has been made. The base-case NPV and IRR are calculated at an assumed investment decision date of 30 September 2029 and exclude pre-development capital scheduled before that date (see Economic Analysis). The spot price case is a sensitivity only and is not a forecast.

PFS Highlights

• Maiden Mineral Reserve: Probable Mineral Reserves of 12.58 Mt at 1.20% Cu and 3.7 g/t Ag, containing approximately 151,400 t (334 Mlb) of copper and 1.50 Moz of silver, effective 1 November 2026. The Probable Mineral Reserve contains about 89% of the copper in the Indicated Mineral Resource.
• Key assumptions (base case): US$5.30/lb copper, US$50/oz silver, C$1.39 per US$1.00 and a 7% discount rate. Concentrate terms provided by American West: treatment charge US$25/dmt, refining charge US$0.025/lb payable copper, copper payable after a deduction of 1.15 to 1.45 units by concentrate grade, and silver payable at 100% above a 30 g/t deduction and a silver refining charge of US$0.50/oz payable. Concentrate shipping is US$85/wmt, insurance and brokerage are 0.33% of cargo value, and concentrate moisture is 2.5%.
• Spot price case: at spot prices of US$6.53/lb copper and US$49.98/oz silver on 2 November 2026, provided by American West, the after-tax NPV7% is C$323.8 million (US$233.1 million), the IRR is 55.1%, and payback is 2.7 years, on the same valuation basis as the base case. The spot case uses the base-case mine plan and Mineral Reserves.
• Capital (incl. C$23.66 million contingency): pre-development C$37.90 million (October 2028 to March 2029), initial C$112.58 million (October 2029 to March 2030) and expansion C$14.21 million (October 2031 to March 2032), for a total of C$164.69 million. Closure and reclamation: C$9.70 million, an allowance provided by American West.
• Production: 688,290 dmt of concentrate at an average grade of 14.97% Cu and 45.8 g/t Ag, containing 103,035 t (227.2 Mlb) of copper and 1.01 Moz of silver. LOM recoveries are 68.2% for copper and 67.5% for silver. Payable metal is 208.2 Mlb of copper and 351.6 koz of silver. Silver is payable at 100% above a deduction of 30 g/t in concentrate.
• Operating costs: LOM average site operating cost of C$72.00 per tonne processed: mining C$47.70/t (contractor rate of C$7.21 per tonne mined, including pre-stripping), processing C$13.29/t and G&A C$11.01/t.
• Cash costs: C1 cash cost of US$3.45/lb and AISC of US$3.73/lb of payable copper in the base case (US$3.45/lb and US$3.91/lb in the spot case), after silver credits (see Non-GAAP Measures).
• Mine plan: 83.28 Mt of total material mined, including 12.58 Mt of ore and 70.70 Mt of waste, for a strip ratio of 5.6:1. Processing runs from April 2030 to April 2040.
• Offtake and finance: a binding offtake agreement with Ocean Partners (July 2025) covers 100% of the base production of copper, silver and gold products from Storm. Ocean Partners has agreed to provide debt finance of up to 80% of initial capital, subject to a bankable feasibility study and formal documentation; this is not committed funding. The PFS economic analysis is unlevered.
• The PFS envisions all infrastructure on-site to be built in three phases; with pre-development capital to target all required infrastructure to support construction at the next phase, initial capital for all infrastructure to be installed to be operational in Years 1 & 2, and the expansion phase to build infrastructure to satisfy the increased throughput in Year 3

Management Commentary

"The pre-feasibility study and maiden Mineral Reserve mark an important milestone in evaluating Storm's potential to create value for Aston Bay shareholders," said Thomas Ullrich, Aston Bay CEO. "The study provides a foundation for further technical work and assessment of potential development, but it does not capture the Project's full exploration upside. The spot-price sensitivity further illustrates Storm's leverage to copper prices, with an after-tax NPV at a 7% discount rate of approximately C$265 million, including all capital, on a 100% project basis. This highlights the potential for additional value at copper prices above the base-case assumption, separate from the exploration upside. Exploration and resource-expansion work are expected to continue, offering significant potential to create additional value beyond the current mine plan. Importantly, Aston Bay's 20% interest remains free-carried for both ongoing exploration and work to advance the project toward a potential mine development decision, including completion of a bankable feasibility study. This gives our shareholders exposure to both development progress and exploration upside without Aston Bay having to fund its share of project expenditures until a decision to mine.

"For Nunavut, Storm's potential development represents an opportunity to generate employment, training and business opportunities for Inuit and northern communities. Whether and how those benefits could be realized would depend on further studies, meaningful engagement with Inuit rights holders and communities, the required assessments and approvals, and project financing. Storm's location in the Canadian Arctic also adds a strategic dimension to its potential. As a prospective new Canadian source of copper, the project could contribute to more secure and diversified critical minerals supply chains while supporting long-term economic activity in the North. Our focus, together with our operating partner, American West Metals, is on evaluating that opportunity responsibly."

PFS Summary

Table 1: PFS Assumptions and Results Summary (100% Project Basis)

Base case unless stated. Results are from the PFS financial model (261102 Storm PFS Model v1.6 (Final) - with Spot): unlevered, 100% Project basis, real terms. NPV and IRR are at 30 September 2029, the assumed date of the investment decision, and exclude C$37.90 million (US$27.3 million) of pre-development capital; the tax deductions and investment tax credits on that capital are included. Payback is measured in annual periods from the start of production in April 2030 and includes all capital, including the pre-development capital. The funding requirement covers pre-development and initial capital, pre-production costs and initial working capital. Totals may not add due to rounding.

Mineral Resources and Mineral Reserves

The Mineral Resource Estimate ("MRE") has an effective date of 23 December, 2025 and was prepared by Mr. K. Hon, P.Geo., of APEX Geoscience Ltd. in accordance with the CIM Definition Standards (2014) and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (2019). The MRE was reviewed and accepted by the responsible QP Mr. Yungang Wu, M.Sc., P.Geo., of P&E Mining Consultants Inc.

Mineral Resources are reported at a 0.25% Cu cut-off grade within a conceptual open-pit shell.

Table 2: Storm Mineral Resource Estimate (effective date 23 December 2025)

Values are rounded for presentation, and classification totals may not sum due to rounding.

Notes to the Mineral Resource table:

1. Mineral Resources are classified in accordance with the CIM Definition Standards (2014) and have an effective date of 23 December 2025. The estimate was prepared under the supervision of, and approved by, Yungang Wu, P.Geo., of P&E Mining Consultants Inc., a Qualified Person as defined by NI 43-101.
2. Mineral Resources are reported inclusive of Mineral Reserves.
3. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing or other relevant issues. The Qualified Persons are not aware of any such issue that would materially affect the estimate.
4. Inferred Mineral Resources have a lower level of confidence than Indicated Mineral Resources and cannot be converted to Mineral Reserves. It is reasonably expected that the majority of the Inferred Mineral Resource could potentially be upgraded to an Indicated Mineral Resource with continued exploration.
5. The October 26 workbook reports a 0.25% Cu cutoff and identifies the shell as v2026_3_55deg. For the purposes of RPEEE a conceptual pit was constructed that utilized a copper price of $US6.05 per pound, mining costs of $US4 and 5 per tonne for waste and mineralized material, $US7 per tonne for G&A and $US6 per tonne for processing and recovery of 80% for copper.
6. Grades were estimated into 5 m × 5 m × 2.5 m blocks within mineralized domains by Ordinary Kriging (OK) with locally varying anisotropy (LVA) using 1.5 m composites with a balanced approach and with variable high-grade capping by domain.
7. Bulk density was assigned by geological formation using median values of 2.73 to 2.80 g/cm³.
8. The drill database closed 23 December 2025 and includes 235drill holes that intersect the mineralization domains.
9. No Measured Mineral Resources are defined. Tonnes are reported in thousands of dry tonnes and contained silver in thousands of troy ounces. Tonnes, grades and contained metal are rounded; totals may not sum due to rounding.

The Mineral Reserve Estimate has an effective date of 1 November 2026 and was prepared by Shervin Teymouri, P.Eng., of Sacré-Davey Engineering Inc., in accordance with the CIM Definition Standards (2014) and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (2019). The Mineral Reserves are included in the Mineral Resources and are derived only from Indicated Mineral Resources within the PFS pit designs.

Table 3: Storm Probable Mineral Reserves (Effective Date 1 November 2026)

1. The Mineral Reserve Estimate has an effective date of 1 November 2026. It was prepared by American West personnel and was reviewed and approved by Shervin Teymouri, P.Eng., of Sacré-Davey Engineering Inc., who takes responsibility for it, in accordance with the CIM Definition Standards (2014) and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (2019). Mineral Reserves are included in the Mineral Resources. Only Indicated Mineral Resources within the PFS pit designs are converted to Probable Mineral Reserves. No Measured Mineral Resources are defined, so no Proven Mineral Reserves are reported. Inferred Mineral Resources are treated as waste. The Probable Mineral Reserve contains about 89% of the copper in the Indicated Mineral Resource. Mineral Reserves were derived from the Mineral Resource estimate through pit optimization, staged pit design (four pits, 15 stages) and production scheduling. They are limited to Indicated material scheduled for processing in the PFS production schedule and are supported by a positive cash flow in the PFS economic analysis.
2. Mineral Reserves are reported at the base-case prices of US$5.30/lb copper and US$50/oz silver and C$1.39 per US$1.00. The base-case economic analysis demonstrates that extraction is economically viable on the assumptions stated in this news release, including the exclusion of sustaining capital, a water treatment plant and the owner's mining technical team and grade control, and the closure cost allowance provided by American West.Cut-off grades are 0.33% Cu at Cyclone, 0.32% Cu at Chinook, 0.33% Cu at Corona and 0.34% Cu at Thunder, at or above the breakeven grades calculated from the inputs in notes 6 to 8. Ore above 0.5% Cu is generally sent directly to the process plant; ore between the cut-off grade and 0.5% Cu is stockpiled for later processing. The Mineral Reserves include about 2.9 Mt of ore between the cut-off grade and 0.5% Cu, stockpiled and processed mainly after mining ends in July 2038.
3. Dilution is included by converting Mineral Resource blocks to whole-block grades on 2.5 m × 2.5 m × 2.5 m selective mining units of about 45 t. Dilution ranges from about 14% (Corona) to 24% (Chinook) and averages 15.6%. An operational ore loss of about 1% is applied, through additional factors at Chinook and Corona and within the reblocked models at Cyclone and Thunder.
4. Process recoveries vary with head grade and are calculated from deposit-specific recovery equations. Cut-off calculations use copper recoveries of 68.4% (Cyclone, Corona and Thunder) and 70.4% (Chinook). The LOM average copper recovery in the PFS production schedule is 68.2%.
5. Cut-off cost inputs, in US$: processing US$9.71/t and G&A US$8.63/t processed; ore differential mining cost US$1.59/t (Cyclone), US$1.47/t (Chinook), US$1.82/t (Corona) and US$1.86/t (Thunder); waste mining cost US$5.88/t to US$6.16/t mined (C$8.17/t to C$8.56/t). These mining costs exceed the contract rate of C$7.21/t us