The Client Conversation: Three Questions That Matter
In 2025, investors in physically-backed gold ETFs earned roughly 65% on their money, making it gold’s best calendar year since 1979. Over the same period, investors holding broad futures-based commodity funds earned single-digit returns. Both groups had “commodity exposure.” One group made a fortune. The difference had nothing to do with which commodities were in the portfolio and everything to do with how the fund accessed them.
That gap between structure and outcome is the central challenge of commodity investing for advisors. Most clients who ask about commodities are thinking about the underlying asset: gold, oil, agricultural products, metals. But the fund structure sitting between the investor and the commodity determines the return just as much as the commodity price itself. A client who watches crude oil rise 15% over a year might reasonably expect their oil ETF to have done something similar. In many cases, it has not, and the explanation involves mechanics that most advisors encounter only when a disappointed client calls.
The Three Structures
Commodity funds come in three basic forms, each with distinct mechanics, costs, and risk profiles that advisors should understand before making any allocation.
Physically-Backed ETFs hold the actual commodity in vaults or warehouses. Each share represents ownership of a specific quantity. The SPDR Gold Shares ETF (GLD), with roughly $148 billion in assets under management as of late 2025, is the most prominent example. The iShares Gold Trust (IAU) holds approximately $69 billion, and the SPDR Gold MiniShares Trust (GLDM) charges 0.10%. The iShares Gold Trust Micro (IAUM), at 0.09%, carries the lowest expense ratio among physically-backed gold ETFs. Silver has a major physically-backed option in the iShares Silver Trust (SLV), which held approximately $38 billion in assets by year-end 2025.
The advantage of physical backing is simplicity: the ETF’s value tracks the spot price of the commodity with minimal deviation. If gold rises 10%, a physically-backed gold ETF rises approximately 10%, minus the expense ratio. There are no roll costs, no contango effects, and no futures contract mechanics to understand. The limitation is that physical backing works only for commodities that are practical to store. Gold and silver work because they have high value relative to their weight and do not deteriorate. Oil, natural gas, livestock, and agricultural commodities cannot be held in ETF form.
Futures-Based Funds do not own barrels of oil or bushels of corn. They own contracts that represent the obligation to buy or sell the commodity at a specified future date. Because futures contracts expire (typically monthly), a fund that wants continuous exposure must “roll” its contracts: selling the expiring contract and buying a longer-dated one. The economics of that roll can dramatically affect returns, as we will see in the next section.
Futures-based funds provide access to commodities that cannot be physically stored, which covers most of the commodity universe. The iShares S&P GSCI Commodity-Indexed Trust (GSG) and the Invesco Optimum Yield Diversified Commodity Strategy No K-1 ETF (PDBC) are among the more widely held broad commodity futures funds. Single-commodity futures funds like the United States Oil Fund (USO) offer concentrated exposure to individual markets.
Exchange-Traded Notes (ETNs) add a third structural option. An ETN is an unsecured debt obligation of the issuing bank that promises to pay a return linked to a commodity index. The investor does not own any commodities or commodity futures. ETNs avoid some tax complications of futures-based funds (no K-1 forms, potentially more favorable income treatment) and can track an index precisely without concern about roll costs affecting fund-level returns.
The critical disadvantage is credit risk. An ETN is only as good as the issuing bank’s promise to pay. If the bank encounters financial difficulty, ETN holders become unsecured creditors. This risk materialized during the 2008 financial crisis when several bank issuers faced severe stress, and it remains a consideration for any long-term commodity allocation held through an ETN structure.
Where Contango Eats Returns
The most important concept in commodity fund investing is one that most clients have never heard of. When longer-dated futures contracts cost more than nearer-dated contracts, a condition called contango, the monthly roll generates a loss. The fund sells the cheaper expiring contract and buys the more expensive longer-dated contract, month after month, quietly eroding returns even when the underlying commodity price is flat or rising.
The reverse condition, backwardation, occurs when nearer-dated contracts cost more than longer-dated contracts. In backwardation, the roll generates a gain: the fund sells the more expensive expiring contract and buys the cheaper longer-dated contract. The distinction matters enormously over time.
The United States Oil Fund (USO) provides a textbook case. Over the ten years ending January 2022, USO delivered an annualized return of approximately -14.6%, while spot crude oil prices were roughly flat over the same period. Persistent contango in oil markets generated roll costs that consumed the investment from the inside. In April 2020, during the COVID-related demand collapse, oil futures markets entered extreme contango. A single one-month roll from April to May contracts resulted in the fund holding nearly 5% fewer contracts, a cost that, annualized, would exceed 75%. USO lost approximately 78% of its value in the first several months of 2020 alone.
The story reversed during 2021 through 2024, when oil markets shifted into persistent backwardation. Over this period, USO actually outperformed the spot price of WTI crude by a wide margin, with the fund gaining over 117% compared to approximately 25% for the front-month futures contract. The positive roll yield during backwardation boosted returns rather than eroding them.
This is the part that matters for advisors: contango and backwardation are not predictable in advance. A client who buys a futures-based commodity fund is making an implicit bet not only on the direction of the commodity price but also on the shape of the futures curve. That second bet is invisible to most investors, and it can overwhelm the first.
Index Construction: The Invisible Allocation Decision
Beyond the physical-versus-futures distinction, the choice of commodity index shapes returns in ways that are easy to overlook. The two dominant benchmarks allocate across the commodity universe very differently.
The S&P GSCI weights its components by world production, which results in approximately 60% to 70% energy exposure (primarily crude oil and natural gas). This makes the GSCI essentially an energy index with a commodity wrapper. When oil prices rise, the GSCI rises. When oil prices fall, so does the GSCI, regardless of what metals or agricultural commodities are doing.
The Bloomberg Commodity Index (BCOM) caps any single sector at 33% and any individual commodity at 15%. This creates substantially more diversified exposure, with energy typically representing 30% to 35%, metals (precious and industrial) another 30% to 35%, and agriculture and livestock making up the remainder. The different weighting produced very different outcomes in recent years.
Table: Commodity Index Returns, 2021-2025
| Year | S&P GSCI Total Return | BCOM Total Return |
|---|---|---|
| 2021 | 40.4% | 27.1% |
| 2022 | 26.0% | 16.1% |
| 2023 | -4.0% | -7.9% |
| 2024 | 0.6% | 5.4% |
| 2025 | Positive (gold-driven) | ~16% (precious metals +64%) |
In 2025, the divergence was stark. BCOM’s sector caps gave it substantial precious metals exposure that contributed as gold and silver surged. The GSCI’s energy-heavy weighting dragged its performance lower as oil prices remained range-bound. An advisor who said “I added commodity exposure” without specifying which index was really making an allocation decision they may not have recognized.
A newer approach, the Bloomberg Commodity 3 Month Forward Index (BCOMF3), positions holdings in the third-month futures contract rather than the front-month contract. Over the past 20 years, this strategy has outperformed the headline BCOM by approximately 5% annually, with most of the advantage coming from reduced roll yield drag. The futures curve tends to be less steep further from expiration, which means less contango cost. Several ETFs now offer access to optimized roll strategies, though advisors should verify that the expense ratios do not consume the roll benefit.
The Inflation Hedge Question
Clients often arrive at the commodity conversation through inflation concerns. The idea that commodities protect against inflation has a long history and a complicated track record.
In certain inflationary regimes, commodities have delivered on the promise. During the 2021-2022 period, when U.S. inflation exceeded 9%, the BCOM gained 27% and 16% in consecutive years. During the 1970s inflationary spiral, commodity prices rose dramatically. The relationship is real, but it comes with conditions that advisors should understand.
First, commodities tend to respond to unexpected inflation, not expected inflation. When inflation is already priced into expectations, commodity prices have already adjusted. The protection arrives when inflation surprises to the upside, which is precisely when investors most want it but also when it is most difficult to implement.
Second, the long-term real return of commodities as an asset class has historically been close to zero. The S&P GSCI Commodity-Indexed Trust (GSG), a proxy for broad futures-based commodity exposure, has returned approximately 1.45% annualized over the past 30 years, which is well below the rate of inflation over that period. The inflation-adjusted annual decline of the CRB Index over its full history has been roughly 1% per year. Commodities, in aggregate, have not been a wealth-building asset class.
Third, gold is an exception that proves the rule. Physically-backed gold ETFs have delivered strong returns over the past several years, with gold rising from approximately $2,060 per ounce at the start of 2024 to over $5,000 per ounce by early 2026. Central banks purchased over 1,000 tons of gold in each of the three years from 2022 through 2024, roughly double the annual pace of the prior decade. Purchases in 2025 remained elevated at 863 tons. Gold has functioned as a store of value and a safe-haven asset during periods of geopolitical uncertainty, but this performance is specific to gold and should not be extrapolated to commodities broadly. An investor who buys a broad commodity futures fund expecting “gold-like” returns is likely to be disappointed.
The honest answer for clients is that commodities can help protect a portfolio during inflationary surprises, but the protection is not free. Roll costs in futures-based products, the cyclicality of commodity prices, and the near-zero long-term real return mean that a permanent commodity allocation functions more like insurance than investment. And like insurance, the cost of the premium matters.
Current Market Snapshot
The commodity fund landscape has evolved dramatically from the small, niche category it was a decade ago. As of year-end 2025, the commodity ETF universe encompasses approximately 72 funds with combined assets under management of roughly $405 billion. U.S.-listed physically-backed gold products alone account for roughly $280 billion of that total, reflecting gold’s dominance of the category.
Table: Largest Commodity ETFs by Assets Under Management (Year-End 2025)
| Fund | Ticker | Structure | AUM (Approx.) | Expense Ratio |
|---|---|---|---|---|
| SPDR Gold Shares | GLD | Physical gold | $148B | 0.40% |
| iShares Gold Trust | IAU | Physical gold | $69B | 0.25% |
| iShares Silver Trust | SLV | Physical silver | $38B | 0.50% |
| SPDR Gold MiniShares | GLDM | Physical gold | $34B | 0.10% |
| Invesco Optimum Yield | PDBC | Futures (broad) | ~$5B | 0.59% |
| iShares GSCI Commodity | GSG | Futures (broad) | ~$2B | 0.75% |
The concentration is instructive. Physically-backed precious metals products dominate the category by a factor of more than ten, which reflects both gold’s strong performance and investors’ revealed preference for the simpler, more transparent structure. Broad commodity futures funds remain a small fraction of total commodity ETF assets despite offering exposure to a wider range of commodities.
The Client Conversation: Three Questions That Matter
When a client expresses interest in commodity exposure, the most productive approach is to start with three questions rather than three recommendations.
What are you trying to accomplish? A client hedging against inflation has different structural needs than one making a tactical bet on oil prices or one who wants gold as a safe-haven asset. The objective determines the structure. For long-term strategic allocation, physically-backed gold or silver ETFs avoid the roll cost problem entirely. For tactical views on energy or agricultural commodities, futures-based funds provide the access, but the holding period should be short enough that roll costs remain manageable. For clients who want broad commodity diversification, a BCOM-based product with sector caps provides more balanced exposure than an energy-dominated GSCI tracker.
How much are you allocating? Research suggests that commodity allocations below 4% to 5% of a portfolio have minimal impact on portfolio characteristics, while allocations above 10% to 15% introduce volatility that may exceed the diversification benefit. A range of 5% to 10% is where most practitioners find the allocation large enough to matter but small enough to tolerate the commodity cycle. Within that allocation, diversifying across structures (some physical gold, some broad commodity exposure) reduces dependence on any single product or market regime.
How long are you holding? This question matters more for commodities than for almost any other asset class. A futures-based commodity fund held for five years through a period of persistent contango can lose a substantial portion of its value to roll costs alone, even if the underlying commodity prices are unchanged. If the client’s time horizon extends beyond two or three years, the conversation should emphasize physically-backed precious metals or, for broader exposure, roll-optimized index strategies rather than standard front-month futures products.
The answers to these three questions do more to determine the right recommendation than any forecast about where oil or gold prices are headed. Structure selection is the decision that compounds over time.
Key Takeaways
- Physical backing eliminates roll costs. Physically-backed gold and silver ETFs track spot prices directly, with minimal deviation. Futures-based funds, by contrast, face monthly rolling decisions where contango (longer-dated contracts trading at a premium) can silently erode returns. The USO fund lost approximately 78% in early 2020 due entirely to extreme contango roll costs—the actual price of oil barely moved in the same period.
- Index construction shapes returns dramatically. The S&P GSCI weights commodities by production (60-70% energy) while the Bloomberg Commodity Index caps sectors at 33%. In 2025, BCOM surged with precious metals exposure while GSCI lagged with energy-heavy weighting. An advisor’s allocation decision is often really an index selection decision, sometimes without realizing it.
- Contango and backwardation are unpredictable. Futures curve shape determines roll yields but cannot be forecasted in advance. Clients buying futures-based commodity funds are making an implicit bet on the shape of the curve—an invisible bet that most investors do not know they are making and that can easily dominate outcomes.
- Commodities are not a wealth-building asset class in aggregate. Broad commodity futures (GSG proxy) have returned approximately 1.45% annualized over 30 years, well below inflation. Commodities function more like insurance against inflation surprises than investment vehicles. Gold is a rare exception that has delivered substantial returns recently, but gold performance should not be extrapolated to commodities broadly.
- Time horizon matters as much as asset selection. A futures-based commodity fund held for five years through persistent contango can lose substantial value to roll costs alone, regardless of commodity price moves. Physically-backed precious metals work better for longer-term strategic allocation; front-month futures need shorter holding periods.
- Three questions trump recommendations. Ask clients: What objective are you trying to accomplish (hedge, tactical bet, safe-haven)? How much are you allocating (below 4-5% has minimal impact; above 10-15% introduces excessive volatility)? How long will you hold (time horizon determines which structure makes sense)?
The Advisor’s Edge
The data in this article is available to anyone with a brokerage account and a web browser. Commodity ETF prices, index returns, contango levels, and AUM figures are published daily. A client can look up GLD’s performance or Google what contango means.
What the data does not provide is the analytical framework for matching fund structure to a client’s actual objective. Recognizing that a broad commodity futures fund and a physically-backed gold ETF serve fundamentally different portfolio purposes. Understanding when roll costs are likely to dominate returns and when they will not. Evaluating whether a client’s inflation concern is best addressed by commodities, TIPS, or a different approach entirely. Integrating a commodity allocation into a portfolio where it improves risk-adjusted outcomes rather than simply adding volatility.
These are the skills that the Certified Fund Specialist (CFS) designation develops: the ability to look beyond product labels and evaluate how a fund’s structure, costs, and underlying mechanics affect the investor’s experience. In a category where structure shapes returns as much as the commodity itself, that analytical depth is the difference between an informed recommendation and a guess.
For more on how fund evaluation frameworks apply across complex product categories, see Portfolio Diversification for Risk Reduction: What the Research Shows.
Sources and Notes: Gold price data from World Gold Council and LBMA. Commodity index returns from Bloomberg (BCOM) and S&P Dow Jones Indices (GSCI). ETF asset and performance data from issuer disclosures and ETF Database. Central bank gold purchase data from World Gold Council Gold Demand Trends reports. USO performance analysis based on published NAV data and Money for the Rest of Us research. Roll yield analysis from Bloomberg Professional Services and CME Group research. All figures reflect year-end 2025 data unless otherwise noted. This article is refreshed annually.