Will Grasberg PB2/3 underground mill throughput reach 80% of nameplate capacity by Q3 2026?
Current Prediction
Why This Question Matters
Grasberg restart execution is the most immediate operational variable, flagged as a material condition across four lenses. Management guidance assumes 60% of copper and 75% of gold production in H2 2026, creating asymmetric downside exposure to restart delays. If PB2/3 reaches 80% capacity by Q3, it validates the back-weighted guidance and supports CONDITIONAL revenue durability. If throughput lags, it would trigger a production guidance revision and directly impair H2 earnings.
Prediction Distribution
Individual Predictions(9 runs)
Management explicitly guides to 60K tpd H2 2026 (60% of nameplate) — this is on the WRONG side of the 80% threshold. Reaching 80% by Q3 2026 would require the wet:dry ratio to improve naturally AND silminator installation to accelerate significantly. Management stated the mid-2027 target is 90K tpd; reaching 80% in Q3 2026 would mean beating their own guidance by 4-6 months. Probability should be well below the pre-earnings 38% — closer to 10-15%.
Management provided quantitative guidance. Reaching 80K tpd by Q3 2026 requires silminator installation to complete faster than the multi-month fabrication/installation cycle, AND either the wet:dry ratio to self-correct (which management said is possible but not in forecast) OR the first installed silminators to dramatically outperform. Mark Johnson described a phased installation approach with equipment still arriving. 10% probability.
Management did acknowledge upside: 'we could have a situation where the material becomes drier as material is mined... we have not counted on that in this forecast.' If wet material shifts dry spontaneously AND blending can handle residual wet panels, the existing chutes could support higher throughput without requiring all silminators. This upside pathway is specifically mentioned by management as possible but not base case. 15% reflects the acknowledged upside case.
The question resolution is binary on an 80K tpd threshold. Management guides to 60K H2 2026. The gap (20K tpd = 33% above guidance) is not something that happens from incremental progress — it requires a step-change either via wet material improvement or accelerated silminator deployment. Both are possible but both would need to be outside management's current base case. 12%.
Mining operations can surprise in both directions. The September 2025 incident itself was an 'unforeseen' operational surprise. Similarly, if the wet:dry ratio normalizes faster than expected or silminator installation is more rapid, Q3 2026 throughput could exceed guidance. However, the evidence presented in Q1 call (wet panels sampling, engineering analysis) suggests the constraint is physical rather than conservative forecasting. 14%.
Direct arithmetic from management guidance: 60K tpd H2 2026, 90K tpd mid-2027. Linear interpolation places Q3 2026 at approximately 65-70K tpd — still well below 80K threshold. For YES resolution, ramp would need to be significantly front-loaded or meaningfully accelerate. 10% is the base rate for Q3 specifically hitting 80%.
Management guides 60K tpd H2 2026 — below 80% threshold. Silminator timeline multi-month. Low probability of Q3 hitting 80%. 12%.
Management acknowledged upside possibility (wet material improving naturally). Small probability of outperformance. 15%.
Mid-2027 target of 90K tpd. Q3 2026 at 80K would be significant acceleration. 12%.
Resolution Criteria
Resolves YES if FCX reports or discloses in Q3 2026 earnings (or interim operational update) that Grasberg underground mill throughput has reached at least 80% of nameplate capacity (approximately 200,000 tonnes per day combined across PB2/PB3). Resolves NO if throughput remains below 80% of nameplate through Q3 2026 reporting.
Resolution Source
Freeport-McMoRan Q3 2026 earnings press release, 10-Q filing, or interim operational update
Source Trigger
Grasberg PB2/3 restart date and initial throughput rates
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