The price quoted in market reports is the wholesale price for large bars. What a retail buyer pays is that figure plus a premium that has its own supply and demand.
Spot describes wholesale metal only
The benchmark price refers to large accredited bars held in recognised vaults and traded between institutions in quantities far beyond what any individual buyer would consider.
A one ounce coin is an entirely different product. The metal in it has to be refined to coin standard, cast into blanks, struck, inspected, packaged and distributed before it reaches a counter.
The premium covers that transformation and the distribution chain behind it, which makes it a manufactured goods price rather than a commodity price, with its own costs and its own capacity limits.
Fabrication capacity is the binding constraint
Mints and refiners operate a fixed number of production lines, and output cannot be increased quickly because the equipment and the certified processes take time to add.
When retail demand surges, orders exceed that capacity and the queue for finished product lengthens.
Premiums rise to ration the available supply, which is why they can climb steeply while the underlying metal price is falling.
Dealer inventory position amplifies the move
Dealers hold stock and set premiums according to what they can replace it for, not what they paid.
When replacement is uncertain, they raise premiums to slow sales and protect inventory, and when stock builds up they cut them to move it.
Both responses are rational for the dealer and they make retail premiums more volatile than the metal price itself.
Premiums fall more slowly than they rise
A demand surge lifts premiums quickly, because the constraint appears immediately and dealers reprice within days.
The decline afterwards takes longer, since dealers work through inventory bought at elevated cost and are reluctant to sell it at a loss.
Buyers entering during a surge therefore frequently pay a premium that is still unwinding when they come to sell.
The effect is largest on the smallest products
Fabrication cost per ounce is highest on small coins and bars, so those products have the most premium available to expand.
Large bars sit closest to the wholesale market and their premiums move far less, which is one reason large holdings are cheaper to build.
A buyer comparing quotes against the spot price is therefore comparing against a number that describes a different product in a different market.