What if a collapse floods Freeport's Grasberg copper-gold mine?
A Grasberg mud rush halting Indonesia's largest copper-gold mine for a year removes a major concentrate block — copper and Freeport move directly on the supply hit (and gold byproduct loss). This is the literal Sep-2025 Grasberg event in the analogues, which tightened the concentrate market and supported Comex copper. Forward angle: with TC/RCs already collapsing toward zero, a Grasberg outage stacks on smelter feed scarcity, amplifying the refined-copper squeeze beyond the headline concentrate loss.
how we built this number — every step
The class rate is measured from our dated, sourced event library (decade-normalized Poisson — the full table is public at base_rates.json). The variant’s share within its class is the analyst’s editorial call, published so you can audit it. A wider range means thinner precedent. Full recipe: methodology · scored at Reality Check.
The butterfly cascade
How this trigger trickles across markets, left → right — the root shock, its first‑order moves, then the ripple effects. Drag any node; tap a market for its real price history.
Resolution timeline — how this probability is moving
Our model's odds (gold) over time vs the crowd's (Polymarket, blue), from the past toward the 0–6 months horizon. Each dot is a real macro event that nudged the probability — green pushed it up, red pushed it down. Tap a dot for the source. The gold path is an illustrative reconstruction anchored to today's estimate — real dated events, not a live re-estimate history.
What it would mean
If this plays out, it is a mixed shock. A mud rush floods Freeport's Grasberg underground mine, halting Indonesia's largest copper-gold operation for over a year. The trigger decomposes into signed root‑shocks — Copper ▲ · Industrial demand ▲ — which propagate through our causal graph to the markets below.
If it happens — the markets it would move
Biggest moves first. Projected moves are cascade-model priors; hist A–B% = what comparable past events actually did (measured abnormal returns), and model prior · unmeasured marks markets with no analogue backing yet. Tap any market for its price history.
| Market | Class | Projected move | |
|---|---|---|---|
| 1 | Freeport (copper) FCX 📈 chart | Equity | ▲ +1.1% hist -1.83–+1.03% · other way +4.9% (n=12) |
| 2 | Copper XCUon Hyperliquid 📈 chart | Commodity | ▲ +1.0% hist +0.04–+0.72% · other way -0.49% (n=12) |
Probable recommendation
Why we may diverge from history
Trust history's FCX short: the very top analogue IS this event (Grasberg mud-rush, -14%) — FCX sells its own supply shock; the cascade's bullish 'tighter copper=higher FCX' is exactly what realized history refutes.
Historical precedent — what analogous events actually did
Across 40 analogous events (overlap‑weighted), as abnormal returns — market beta stripped, so it's the event's own effect, not the market backdrop. Shown at 20 days (persistent) and 5 days (immediate); ↺ fades = the two horizons disagree. Confidence = consistency × sample × significance.
| Asset | History says | Abnormal (20d · 5d) | Hit | n | Confidence | vs cascade |
|---|---|---|---|---|---|---|
| FCX FCX | SHORT | -2.1% · 5d -1.7% | 62% | 40 | 0.22 | ⚠ differs |
| High-yield credit HYG | SHORT | -0.4% · 5d -0.1% | 60% | 40 | 0.16 | · |
| Volatility VIX | LONG | +4.1% · 5d -0.7% ↺ fades | 55% | 40 | 0.08 | · |
| XCU XCU | SHORT | -0.4% · 5d -1.0% | 53% | 40 | 0.04 | ⚠ differs |
| Bitcoin BTC | LONG | +3.4% · 5d -1.8% ↺ fades | 51% | 39 | 0.02 | · |
| Gold XAU | SHORT | -0.1% · 5d -1.1% | 45% | 40 | 0.00 | · |
| US dollar DXY | SHORT | -0.0% · 5d +0.1% ↺ fades | 45% | 40 | 0.00 | · |
| 10y yield DGS10 | LONG | +3bp · 5d +2bp | 45% | 40 | 0.00 | · |
Why this probability
Grasberg already had a 2025 mud-rush; a fresh year-long flood within 6mo is low base-rate. A base‑rate‑anchored prior, continuously scored against what actually happens — not a forecast.