The Oil Chart Is Up, Your Fund Is Down—and It Never Owned a Barrel

The spot price of oil and a futures-based fund can move in opposite directions for months at a time because the fund’s return is built from a chain of contract exchanges, not from the spot market.

The gap is not a hidden fee, though a fee can make it a little wider. Most of it is something the index providers call roll yield, and in a market that has spent most of the past decade in contango, the roll yield has been negative. The reader who watched crude rally over a twelve-month period while their fund posted a loss was almost certainly buying a product that was feeding a contango curve: selling a cheap near-month contract and buying a more expensive one further out, month after month, bleeding returns in increments too small to notice on any single day but large enough to turn a headline gain into a portfolio loss by year-end.

The fund owns a calendar, not a barrel

The S&P GSCI Crude Oil index, the methodology that underpins many oil ETFs, follows a published rolling schedule. It does not wait for a contract to expire before moving on. Instead, well before expiration, the index rolls its exposure into the following month’s contract. This is disclosure number one in the index rulebook, but it is the detail almost every first-time commodity-fund buyer misses. The fund never takes delivery of physical barrels; it is constantly passing positions forward.

What that forward pass costs depends entirely on the replacement price. Fidelity published an example that cuts through the arithmetic: in a contango market, an ETF selling a front-month WTI contract at $100 and buying a second-month contract at $101 buys roughly 1 percent less crude oil because the next contract is more expensive. That lost barrel fraction is not a one-off. It compounds every time the roll happens. Over a full year of monthly rolls, a 1 percent monthly haircut can strip more than 11 percent off the return before any expense ratio enters the picture.

The mechanism works in the other direction too. When the curve is in backwardation—futures prices below the spot price—the fund sells an expensive near-month contract and replaces it with a cheaper one further out. Instead of losing barrels, it gains them. Fidelity notes that backwardation helps investors’ returns. The direction of the curve is not a curiosity; it determines whether the roll is a millstone or a tailwind.

Contango and backwardation are not jargon—they are the cost structure

CME Group defines contango as a futures curve where contracts further out on the curve are priced higher than both the spot price and the front-month contract. Backwardation is the mirror condition: futures prices sit below the spot price. These are observable market conditions, not theoretical constructs, and the shape of the crude curve can stay in one configuration for years.

When a market is in contango, investors pay to roll futures contracts. S&P Global describes this as negative roll yield that drags on index performance. The drag is mechanical. If the index provider’s roll schedule says to sell June and buy July, and July is $3 higher, the roll costs $3 per barrel in notional exposure, and that cost is realized whether the spot price is rising, falling, or standing still. A fund that tracks such an index will underperform the spot price by roughly the cumulative roll yield over the holding period.

Backwardation flips the arithmetic. Selling a rich front-month contract and buying a cheaper deferred contract generates a positive roll yield. In a backwardated market, a futures-based fund can outperform the spot price, because every roll adds fractional barrels. The 2022–2023 energy rally, when the curve moved into deep backwardation after Russia’s invasion of Ukraine, gave commodity funds a roll tailwind that magnified the spot gains. That was the same mechanism working in the investor’s favour—and it is exactly the opposite condition from what the frustrated reader is likely looking at now.

When the front month went negative and the funds had already left

The single most extreme demonstration of the roll mechanism arrived on April 20, 2020, when the May WTI crude oil futures contract settled at negative $37.63 per barrel. The U.S. Commodity Futures Trading Commission later published an interim staff report noting that this was the first time the WTI contract had traded at a negative price in the 37 years since its listing. Physical storage in Cushing, Oklahoma, had filled, and holders of May contracts who could not take delivery were forced to pay buyers to assume the obligation.

Funds that tracked the S&P GSCI Crude Oil index were largely insulated from that particular settlement print. S&P Global confirmed that the index had already rolled out of the May contract and into the June contract before the negative settlement occurred. The June contract was trading at roughly $20 a barrel on the day the May contract collapsed, a gap of nearly $58 between the expiring front month and the next delivery month. An investor who read that oil had turned negative might have expected their fund to be wiped out, but the fund had moved to June exposure on schedule and the published net asset value reflected a $20 contract, not a negative one.

The events of that week put the roll schedule at the centre of the conversation. It became clear that a fund’s return on any given day depended on which month it was holding, not on the spot price everybody was quoting. The spot price many news services were displaying was a blended or prompt-month figure that did not match what any specific fund owned. The divergence was not a failure of the fund; it was a mismatch between the benchmark the public was watching and the contracts the fund actually held.

Fund disclosures showed schedules moving in real time

The stress of April 2020 forced unusual disclosures. USO, the United States Oil Fund, announced on April 21 that because of extraordinary market conditions, including what it described as super contango, it had shifted its portfolio to roughly 40 percent June, 55 percent July, and 5 percent August contracts. It also disclosed a new ten-day rolling schedule beginning with the May 2020 roll, a significant change from its previous methodology. The fund was effectively spreading its exposure further along the curve to reduce the immediate impact of the contango squeeze at the nearby expiries.

Index providers acted as well. Refinitiv, through its CoreCommodity CRB indices, applied a one-off modification to the roll schedule for certain WTI futures contracts to address the exceptional market conditions surrounding the negative settlement. The fact that a major index provider could change its roll schedule in response to a single settlement day told investors something fundamental: the return of a commodity index is not a passive harvest of spot price movements. It is an actively managed sequence of contract selections, and the schedule itself is a variable the provider can adjust when the market structure breaks.

For an investor trying to understand why a fund’s return detached from the spot oil price, these disclosures are the smoking gun. The fund company and the index provider were both making deliberate choices about which contracts to hold and when to roll them. Those choices added up to a return path that had nothing to do with whether the spot price of oil was higher or lower over an arbitrary twelve-month window.

The spot price is the wrong measuring stick

Comparing a fund’s chart with spot crude is the most common error in commodity fund analysis—and it guarantees confusion. The spot price reflects a physical transaction for immediate delivery; the fund reflects a series of futures positions that are rolled forward. When the futures curve is in contango, the fund systematically pays a premium to extend its exposure, so even a flat spot price generates a negative fund return over time because of roll decay. If the spot price rises but the contango is steep enough, the fund can still lose money, which is precisely what the frustrated reader is seeing.

The S&P GSCI Crude Oil index itself was designed to measure a rolling futures position, and its total-return version includes the roll yield along with price changes. S&P Global has stated plainly that contango creates a negative roll yield that drags on index performance. The index total return diverges from the spot return by exactly that drag, plus the interest earned on collateral (a small offset), minus any fees the fund charges on top. An expense ratio of 0.70 percent or 0.85 percent might account for a sliver of underperformance, but the lion’s share of a gap that runs to double-digit percentage points is almost always the roll yield.

The USO disclosure of a ten-day rolling schedule highlights another layer: the exact days on which a fund rolls can matter enormously. Rolling when the nearby contract is under severe selling pressure and the deferred contract is bid up—the conditions that produced the negative May WTI print—can crystallize losses that a fund with a different schedule might avoid or defer. That is why an investor who truly wants to understand the return needs to read the index methodology and the fund prospectus, not simply overlay a chart of spot crude and assume the difference is a fee or a tracking error.

At the end of the period, the curve answers the question

Every story about a futures-based oil fund losing money while crude rises ends at the shape of the forward curve. If the curve spent the bulk of the holding period in contango—with deferred contracts priced above the front month—the roll was a persistent drain. The higher the spot price climbed, the more expensive the next contract became, and the more value the fund surrendered each time it rolled. If the curve had flipped into backwardation instead, the roll would have added to the return, and the fund might well have beaten the spot price.

The next time you see a headline oil price and wonder where your fund’s return went, look first at the curve. Find the contango, measure the spread between the front and second month, and count how many rolls the fund went through during your holding period. That arithmetic, not the spot chart, will show you the missing money. Whether the roll remains a drain depends entirely on whether the market stays in contango—and for how long.