Guanajuato Silver Is Losing Money on Every Ounce It Mines

Guanajuato Silver just recorded the highest realized silver price in its peer group, and it still could not turn a profit on the metal it pulled out of the ground. In Q2 2026, all-in sustaining costs climbed to US$71.66 per silver-equivalent ounce while revenue per ounce produced sat at US$70.62. The company is functionally running its mines at a loss, regardless of what silver is doing on the spot market.

Guanajuato Silver operates a five-mine portfolio in Mexico and has been executing a capital-heavy turnaround since acquiring the Bolaños mine from Endeavour Silver. The Q2 2026 results crystallise the central tension of that strategy: aggressive development spending, framed by management as investment in future production capacity, is producing negative per-ounce margins right now. Whether this is a temporary phase or a structural cost problem is not answerable from the headline figure alone.

This breaks down where the costs are actually coming from, which assets are responsible, how the capital spending cycle connects to the cost surge, and what the numbers look like once peer methodology differences are stripped out. Investors weighing the company’s capital discipline will find the mine-level detail needed to form a defensible view.

A 34% AISC spike on top of already elevated costs

The Q2 2026 number is arresting on its own. It becomes far more concerning when you see the six-quarter run-up that produced it. This is not one bad quarter dropped into an otherwise stable cost base; it is the steepest point on a curve that has been climbing without interruption.

Here is the trajectory, quarter by quarter:

1. Q1 2025: AISC US$23.41/oz as reported, the low point before the acquisition-driven build began.
2. Q2 2025: US$32.97/oz on Research Capital’s methodology-adjusted basis, incorporating offsite costs and conversion ratios.
3. Q4 2025: US$43.12/oz as the Bolaños integration and development spending gathered pace.
4. Q1 2026: US$44.95/oz, holding at the elevated level rather than easing.
5. Q2 2026: US$71.66/oz, a 34% quarter-over-quarter jump as sustaining capital nearly tripled.

The margin inversion is the part that should stop investors cold.

The margin math Revenue per silver-equivalent ounce produced: US$70.62. All-in sustaining cost per ounce: US$71.66. Every ounce produced in Q2 2026 cost more to sustain than it brought in.

This is not purely a sustaining-capital artifact either. Cash costs, which strip out development spending and capture the direct expense of getting metal out of the ground, rose to US$49.08 per silver-equivalent ounce in Q2 2026. That confirms the pressure sits in the operations themselves, not only in the capital line.

Set the current figure against management’s own stated ambition and the gap is stark. Leadership previously aspired to exit 2025 at a run-rate of roughly 3.5-3.75M silver-equivalent ounces annually with AISC around US$22-23/oz. The current cost base is more than three times that end-state target.

What this tells you is that the company is not in a minor deviation from plan. It is operating in a cost environment triple the level leadership once projected as the destination, and the trajectory has been pointing the wrong way for six consecutive reported periods. That reframes the problem from something to wait out into something to actively reassess.

Which mines are driving costs, and why Bolaños matters most

A blended AISC of US$71.66/oz hides more than it reveals. The portfolio is not uniformly expensive; it is a spread running from just under US$45/oz to over US$90/oz, and the dispersion is where the real story lives.

Two mines stand out immediately. Bolaños at US$90.11/oz and Valenciana at US$83.06/oz are operating at costs that would be uneconomic even at the elevated silver prices of Q2 2026. That is the practical meaning of the dispersion: mine-level triage matters far more than the average.

The counterintuitive result is Topia, the lowest-cost mine at US$45.19/oz despite running under a contract arrangement rather than direct operation. That signals operational structure can matter as much as raw asset quality, and it complicates any simple narrative that older or smaller assets are automatically the drag.

The two clear problem assets tell different stories. Valenciana had mining fully suspended in favour of a drilling programme, with throughput down 71% year-over-year. El Cubo milled just 30,000 tons in Q2, down 48% year-over-year, which management attributed to insufficient underground development.

The Bolaños inheritance problem

Bolaños is the highest-cost mine for a specific, disclosed reason: it arrived with an inherited backlog of underground development.

Management’s framing Company leadership attributes Bolaños’s elevated cost structure to a deficit in underground development inherited at acquisition, requiring heavy catch-up spending before the asset can operate at target cost.

An underground development backlog has a direct and unforgiving effect on cost. Insufficient access drives mean fewer working mining faces, which forces reliance on lower-grade stockpile material and spreads fixed costs over reduced tonnage. The per-tonne cost rises even when the mine is being run competently, simply because there is less ore moving through it.

The strategic logic behind buying it anyway rests on synergy. Guanajuato Silver acquired Bolaños from Endeavour Silver for total consideration of up to US$50M, with US$40M upfront (US$30M cash and US$10M in shares). The thesis is that hauling San Ignacio ore to the Bolaños plant cuts the trucking distance from roughly 30 km to about 2 km, feeding an underutilised 1,600 tpd flotation plant.

That underutilised plant is both the upside case and the reason costs are high today. Bolaños contributed only 81,000 silver oz in Q2 against its heavy cost base. The mine has capacity waiting to be filled, but filling it depends on completing the development work that is inflating costs in the meantime.

How capital spending is mechanically inflating AISC

Here is the distinction that changes how the whole quarter should be read. AISC is not purely a measure of how efficiently a company operates its mines. It is a number that investment decisions can deliberately inflate, and knowing that separates an accounting signal from an operational one.

The mechanism sits in the methodology. World Gold Council guidance treats production-phase underground mine development as sustaining capital, which flows directly into the AISC calculation. Any quarter heavy on development drilling and access work will produce elevated AISC by definition, regardless of how tightly operating costs are controlled.

That is precisely what happened. Sustaining capital in the Q2 2026 quarter nearly tripled to US$9.5M, and in Q3 2025 total capital expenditure had already risen 97% quarter-over-quarter. The spending is deliberate and back-loaded, not accidental.

Zoom out to the full-year programme and the scale becomes clear. The 2025 capital budget was US$35M, targeting 75,000 metres of drilling and 16,000 metres of underground development. The 2026 capital budget is also US$35M, described by management as the largest in company history. Management has also indicated costs were not expected to decline meaningfully through Q2 or Q3.

Management guidance on cost persistence With roughly three-quarters of the drilling programme and two-thirds of the capital budget remaining at mid-year, management indicated the programme was flexible but that costs were not expected to decline meaningfully in the near term.

What this tells you is that current margins are being sacrificed for future mining faces. When sustaining capital nearly triples while production stays roughly flat, the question is not whether management made a mistake. It is whether the balance sheet can carry the sacrifice long enough for 2027, the intended beneficiary of this spending, to actually arrive.

What the free cash flow profile reveals

The free cash flow picture is where the sustainability question gets sharp.

• H1 2025: Operating cash flow of US$10.5M was eclipsed by US$11M in capital expenditures.
• Full-year 2025 (estimated): Free cash flow of approximately negative US$3M.
• Cumulative 2020-2024: Free cash flow burn of approximately negative US$63.83M.

That cumulative burn has been financed largely through equity, with the share count expanding nearly five-fold since 2020. The relationship is straightforward: negative free cash flow requires external financing, and the financing has come primarily from issuing shares, which dilutes existing holders.

Sustained positive free cash flow depends on three things happening together: the Bolaños ramp-up delivering volume, grade improvement at El Cubo and San Ignacio lifting revenue per tonne, and capital spending moderating once the current development phase completes. None is guaranteed, and all three are needed.

This is the frame that separates accounting mechanics from genuine deterioration. An AISC spike driven by surging sustaining capex in an acquired asset with a known development backlog is a different risk from a spike driven by rising costs at mature mines. One is self-correcting in principle; the other is structural.

Reading Guanajuato Silver’s costs against its peers

Compare the headline AISC figures across the silver mid-tier and Guanajuato Silver looks like an extreme outlier. Compare them properly, and the picture shifts, though not enough to make the company look cheap.

The methodology gap is the reason these numbers are not directly comparable. Guanajuato Silver does not apply by-product credits and does not use budget silver pricing in its AISC calculation, whereas First Majestic, Endeavour, and Avino present costs net of by-product credits per World Gold Council guidance. Deducting secondary metal revenues mechanically lowers reported AISC, so peers that apply the offset will always print lower numbers even where underlying operations are similar.

Research Capital’s adjusted figure illustrates the spread. On a methodology-consistent basis, Guanajuato Silver’s Q2 2025 AISC worked out to US$32.97/oz, above the company’s own reported figure for that period and far closer to the peer range than the raw headline suggests.

Before comparing any silver producer’s AISC to another’s, check these three factors:

• By-product credit treatment: whether secondary metal revenues are deducted from costs.
• Pricing basis: whether the company uses budget silver pricing or spot pricing.
• Silver-equivalent conversion ratio: which gold-to-silver ratio is applied, given Guanajuato Silver’s shifted from 97:1 to 62:1 year-over-year.

What this tells you is that anyone comparing headline AISC across this group is not comparing equivalent numbers. Guanajuato Silver’s true competitive position is meaningfully better than the raw figure implies, though still materially above its peers even after adjustment. Accept the headlines at face value and you underestimate the company; ignore the methodology entirely and you overestimate it.

What the cost trajectory needs to deliver for this thesis to work

The turnaround thesis is testable, and management has effectively set the exam date. Development spending now is meant to benefit 2027, which gives investors a clean window against which to measure progress. Three variables will determine whether the current spike is a phase or a permanent feature:

1. Bolaños ramp and grade: the acquired mine needs rising throughput and improving grades to justify its US$90.11/oz cost base and fill the 1,600 tpd plant.
2. Legacy mine recovery: El Cubo and Valenciana need underground development to restore the throughput that collapsed 48% and 71% respectively year-over-year.
3. Capital moderation: sustaining capital needs to fall from its near-tripled Q2 level once the development phase completes, so AISC can decompress.

The silver price has been quietly masking how thin the margin really is. At a realized price of US$73.68/oz in Q2 2026, Guanajuato Silver barely cleared breakeven against AISC of US$71.66/oz. That buffer is a function of an unusually strong silver market, not operational strength.

The buffer is already narrowing By late August and early September 2026, spot silver sat around US$66-67/oz, below the US$73.68/oz realized in Q2 2026. The margin that allowed near-breakeven operations is compressing before the development spending has delivered any offset.

With current production annualising to roughly 2.4M silver-equivalent ounces against the 3.5M target, and the price buffer thinning, investors who assumed silver would carry the thesis through the development phase need to reassess that assumption now. If spending has not translated into materially better throughput and grades by mid-2027, the investment case weakens considerably.

This article is for informational purposes only and should not be considered financial advice. Investors should conduct their own research and consult with financial professionals before making investment decisions. Past performance does not guarantee future results, and financial projections are subject to market conditions and various risk factors. Forward-looking statements regarding production ramp-up and cost trajectory are speculative and subject to change based on market developments and company performance.