A metal backed fund trades on an exchange at whatever price buyers and sellers agree, yet it rarely strays far from the value of the metal it holds. A specific mechanism enforces that.
The fund has two prices at once
The first is the market price, set continuously by trading in the shares themselves like any listed security.
The second is the value of the metal held divided by the shares outstanding, which is calculated from the metal price rather than from trading in the fund.
These are produced by entirely separate processes, and nothing about listing a fund forces them to agree.
Authorised participants can exchange one for the other
Designated institutions have the right to deliver metal to the fund in exchange for newly issued shares, or to return shares and receive metal.
These transactions happen in large standard blocks and are settled at the value of the underlying holdings rather than at the market price of the shares.
The right is contractual and continuous, so it is available whenever the two prices differ enough to make using it worthwhile.
The arbitrage closes the gap
If shares trade above the value of the metal, a participant buys metal, delivers it, receives shares and sells them, which increases the supply of shares and pushes the price down.
If shares trade below, the participant buys shares, redeems them for metal and sells the metal, which reduces share supply and lifts the price.
Both trades are profitable only while the gap exceeds transaction costs, so the mechanism operates until the difference is too small to be worth capturing.
Fund size adjusts to demand rather than being fixed
Because shares are created and cancelled continuously, the quantity of metal a fund holds expands when investors buy and contracts when they sell.
This is why reported fund holdings are used as a measure of investment demand: they record metal genuinely moving into and out of vaults.
A closed ended structure without this mechanism behaves differently and can trade at a persistent discount or premium for long periods.
The mechanism depends on physical settlement working
The arbitrage requires metal to be deliverable to the fund's custodian in acceptable form within the settlement period.
Where transport is disrupted, refining capacity is stretched or the required bar specification is scarce, the trade becomes difficult and the gap can widen.
Divergences between a fund's price and its metal value therefore tend to signal physical market stress rather than a problem with the fund itself.