Exchange traded commodities are designed to track a commodity or a commodity index and are traded on a stock exchange in a similar way to exchange traded funds. The key structural point is that the supply of units can typically expand or contract through a creation and redemption process linked to market demand, with authorised counterparties able to bring new units to market or remove units from circulation. This mechanism helps the market price stay close to the value of the underlying exposure and is characteristic of open ended structures. Closed ended vehicles, such as investment trusts, have a fixed number of shares and can therefore trade at a premium or discount to net asset value. In contrast, exchange traded commodity structures are generally intended to minimise persistent premiums or discounts by allowing issuance and cancellation. For exam purposes, the most appropriate classification among the options is open ended, reflecting their ability to adjust the number of units in response to demand and the way they are used as a listed, low friction route to commodity exposure.