Gold mining economics matter to traders through the cost curve: all-in sustaining cost, or AISC, is the cash cost of producing an ounce and sustaining the mine. When the gold price approaches industry AISC, high-cost production becomes uneconomic and supply eventually contracts, which acts as a slow, soft floor rather than a hard price support.
Gold mining economics reach the gold price through the industry cost curve. All-in sustaining cost, or AISC, is the cash cost of producing an ounce plus the sustaining capital, royalties and overhead required to maintain output, and when the gold price approaches industry AISC high-cost production eventually leaves the market.
That mechanism is slow and soft rather than a hard floor: producers mine below full cost for extended periods because closures are expensive, contracts commit them, and deferring sustaining capital temporarily lowers reported cost. Mine supply is highly inelastic, taking five to ten years from discovery to production, while recycled scrap responds to price within weeks.
Miner margin is the gold price minus AISC, and because cost is largely fixed in the short run the margin is leveraged: at a ,400 AISC, gold rising from ,600 to $2,000 is a 25% move in the metal but a 200% move in margin, which is why gold equities amplify metal moves in both directions.