Industry cost curve

Line up every producer of a commodity from cheapest to most expensive, and plot each one's cash cost per unit against cumulative production. You get a rising staircase, and that staircase is the industry cost curve. If you keep one picture from this playbook, keep this one.

 Cash cost
 ($/t)
  2,600 |                                              ┌────
        |                                   ┌──────────┘  D  <- 4th quartile:
  2,300 |                        ┌──────────┘   C            marginal producers,
        |                        │                           set the price,
  2,000 |             ┌──────────┘    B                      die in troughs
        |             │
  1,700 |   ┌─────────┘   A
        |───┘  1st quartile: survives any trough
  1,400 |__A________________________________________________
        0%        25%         50%        75%        100%
              Cumulative global production ->
                                    ^ demand line crosses here:
                                      the intersecting producer's
                                      cost ~ the market price floor

How do you read an industry cost curve?

How to read it:

• The marginal producer sets the price. That's the highest-cost unit of supply the world still needs. If demand requires 96% of global capacity to run, the price has to stay high enough to keep the 96th-percentile producer alive. When demand falls to 85%, price falls toward the 85th-percentile producer's cash cost, and everyone to the right of that point burns cash.
• In a trough, price gravitates toward the cash cost of the ~90th-percentile producer, the classic "cost support" level. Prices can fall below it for a while. Producers will run at cash losses to avoid shutdown and restart costs or to hold market share, and some keep going because a state owns them and cares about jobs. But prices rarely stay down there long. High-cost supply exits, and the curve corrects itself. So analysts obsess over cost curves from CRU, Wood Mackenzie or AME, because you can read the trough price off the curve instead of guessing it.
• The only moat here is being on the left. A 1st-quartile producer earns money at prices that bankrupt the 4th quartile. It survives every trough, buys distressed assets at the bottom and compounds through the cycle. That's a real cost-advantage moat, the kind you met in the moats work, and it usually comes from one of four places. Geology is one: ore grade, strip ratio, open-cast against underground. Location is another, like a mine next to a port. Captive inputs are the third, and India has good examples. Tata Steel has ~100% captive iron ore, Hindalco's Utkal refinery gives it 1st-quartile alumina and Coal India mines shallow open-cast seams. Gas-fed smelters in the Middle East belong on the same list. Scale is the fourth.
• Curves move. A weaker AUD/BRL/INR pushes local-cost producers left on a USD curve. Energy prices shift them too, since power is ~35 to 40% of aluminium smelting cost. And aging mines drift right as grades decline. A company "sliding down the cost curve", drifting from 2nd to 3rd quartile, is losing its only moat. That's red flag #1.

Worked example and cash cost definitions

Worked placement (illustrative, modeled on ~FY24 scale; pull the actual disclosures). A BHP-style Pilbara iron-ore operation reports C1 cash costs around $18 to 20/t, against a benchmark price that has ranged roughly $80 to 130/t over recent years. That's deep 1st quartile. It earns fat margins at prices that would erase most Chinese domestic and small-scale producers, whose costs of $80 to 110/t make up the curve's right tail. That tail is why iron ore's floor kept forming in the $80 to 90 zone in weak years. Now take a Hindalco-style Indian smelter with cash cost near $1,750 to 1,900/t. When LME aluminium trades $2,200 to 2,600, it's low-2nd quartile globally: profitable through most troughs, uncomfortable below $1,900.

Note the vocabulary while you're here. C1/direct cash cost is the site-level operating cost. Total cash cost adds royalties and selling costs. AISC, all-in sustaining cost, adds sustaining capex and site G&A, and it's the gold-mining standard. Check which definition a company is quoting before you compare, because AISC can be 25 to 40% above C1.