Physically Backed vs. Futures-Based Commodity Fund: What's the Difference?
Wanting exposure to a commodity’s price doesn’t necessarily mean owning that commodity. Funds get there two very different ways, and the method matters for cost, taxes, and how closely the fund tracks the price it’s chasing.
The short answer
A physically backed commodity fund holds the actual commodity — gold bars in a vault, for example — so its value moves directly with the spot price of that asset. A futures-based commodity fund instead holds futures contracts tied to the commodity’s price, requiring the fund to regularly roll those contracts forward as they approach expiration, which can cause its returns to diverge from the simple spot price over time.
How physical backing works
With a physically backed fund, the connection to price is fairly direct: the fund owns a defined quantity of the actual commodity, held in storage, and share value tracks that holding’s market value, minus costs like storage and insurance. This structure tends to work well for commodities that are practical to store, such as precious metals, but is far less practical for commodities like crude oil or agricultural products, which are costly or impossible to physically warehouse at scale for a retail fund.
How futures-based exposure works instead
For commodities that aren’t practical to store, funds typically use futures contracts instead, agreements to buy or sell the commodity at a set price on a future date. Because these contracts expire, the fund must continually sell contracts nearing expiration and buy new ones further out, a process called rolling. That rolling process introduces roll yield, a return factor separate from the commodity’s actual spot price movement, which is one of the main reasons a futures-based fund’s long-term return can look meaningfully different from simply tracking the spot price chart.
Why the distinction affects tracking and cost
A physically backed fund’s costs are relatively straightforward, mainly storage, insurance, and management fees reflected in its expense ratio. A futures-based fund’s costs are less visible on the surface, since rolling costs and the effects of contango or backwardation aren’t a simple line-item fee but instead show up as a drag or boost embedded in performance over time. This makes the two structures harder to compare directly using expense ratio alone.
What to weigh between the two approaches
- What’s actually being tracked. A physically backed fund tracks spot price closely; a futures-based fund tracks a rolling futures strategy that can diverge from spot over time.
- Practicality by commodity type. Physical backing works for storable commodities; futures-based structures dominate for commodities that can’t reasonably be stored by a fund.
- Hidden versus visible costs. Storage costs are relatively transparent; roll yield effects are less obvious but can matter just as much over time.
- Comparable structures. This same physical-versus-futures distinction is also central to comparing a commodity ETF against a commodity ETN, which adds a further structural layer on top of this question.
A practical habit
Before assuming a commodity fund simply tracks “the price of gold” or “the price of oil,” it’s worth checking whether it’s built on physical holdings or rolling futures contracts, since that single structural choice can meaningfully shape long-term returns independent of what the commodity itself actually does.