Oil ETFs: Contango Backwardation and Investing
USO can lose money even when oil rises, because it holds futures, not barrels. Understanding contango and backwardation is the key to not getting burned by oil ETFs.
Don't have time? Here's what you need to know:
- 1Oil ETFs like USO hold futures, not barrels, so they track the futures curve — not the spot oil price you see quoted.
- 2In contango (the usual state), rolling contracts creates a drag that can erode returns even when oil is flat or rising.
- 3In 2020, front-month WTI futures went negative and USO absorbed steep roll losses, failing to recover like spot oil.
- 4For long-term oil exposure, energy equity funds like XLE or VDE avoid roll decay and pay dividends; futures funds are trading tools only.
Why Oil ETFs Don't Track the Oil Price
Here is the trap that catches almost every first-time oil investor: a fund like USO does not hold barrels of oil, and it does not track the 'spot' price you see quoted on the news. Storing physical crude is impractical, so these funds hold oil futures contracts — agreements to buy oil at a set price on a future date. That structural choice changes everything about how the fund performs.
Because a futures contract expires, the fund must continually sell its expiring contracts and buy later-dated ones to stay invested. This process, called 'rolling,' is where the money is quietly made or lost. Over time, the cost or benefit of rolling can cause a futures-based oil fund's return to diverge dramatically from the change in the spot oil price — sometimes by tens of percentage points a year.
Contango and Backwardation, Explained Simply
Two terms govern whether rolling helps or hurts you. Contango is when later-dated futures cost more than near-dated ones — the usual state of the oil market. When a fund rolls in contango, it sells low-priced expiring contracts and buys higher-priced later ones, locking in a loss on every roll. This 'negative roll yield' steadily erodes returns even if spot oil is flat. Hold a fund in persistent contango long enough and it bleeds value.
Backwardation is the reverse: later contracts cost less than near ones, often during supply crunches. Here, rolling sells high and buys low, adding a 'positive roll yield' that boosts returns. The crucial point is that the shape of the futures curve, not just the direction of oil prices, determines your outcome. A fund can rise less than spot oil in contango, or even fall while spot oil climbs.
| Curve shape | Later futures vs near | Roll effect | Common during |
|---|---|---|---|
| Contango | More expensive | Negative roll yield (drag) | Normal / oversupply |
| Backwardation | Cheaper | Positive roll yield (boost) | Supply crunch / shortage |
Important: In contango — the oil market's usual state — a futures-based fund like USO can lose value over time even when spot oil prices are flat or rising slowly.
The 2020 Cautionary Tale
The dangers of futures-based oil funds were on full display in 2020. As demand collapsed and storage filled, the front-month WTI futures price briefly went negative — below zero — for the first time in history. USO, holding those front-month contracts, was forced to restructure its holdings, spread across later contracts, and absorb steep roll losses in deep contango. Investors who bought it expecting to 'buy the dip' in oil discovered the fund did not recover anything like the way spot oil did.
The episode is a permanent reminder that an oil ETF is a bet on the futures curve and the fund's mechanics, not a clean wager on the price of crude. Buying a futures-based commodity fund without understanding roll yield is one of the most common and costly mistakes in thematic investing.
Better Ways to Get Oil Exposure
For most investors who want to participate in oil, the cleaner route is energy equities rather than futures. An energy sector ETF like XLE or VDE holds the major oil and gas producers — companies whose profits rise and fall with crude prices, but which also pay dividends and avoid the roll-yield problem entirely. Over long periods, energy stocks have tracked the fortunes of the oil business without the structural decay of a futures fund.
If you genuinely want pure commodity exposure, treat futures-based oil funds as short-term trading tools, not long-term holdings, and read the prospectus to understand how they roll. Some funds (such as the one tracked under BNO, based on Brent crude, or funds that spread across the curve) try to reduce roll costs, but none escape the math entirely. The simplest honest summary: if you do not understand contango, do not buy a futures-based oil fund.
Tip: Want oil exposure for the long run? An energy sector fund like XLE or VDE gives you the producers, pays dividends, and sidesteps the roll-yield decay of futures funds.
Frequently Asked Questions
Why does USO not track the price of oil?
USO holds oil futures contracts, not physical barrels, and must continually roll expiring contracts into later-dated ones. In contango — when later contracts cost more — each roll locks in a small loss, so the fund can fall behind or even decline while spot oil is flat or rising. The fund tracks the futures curve and its own mechanics, not the spot price on the news.
What are contango and backwardation?
Contango is when later-dated futures cost more than near-dated ones, so rolling sells low and buys high, creating a drag (negative roll yield) — this is the oil market's usual state. Backwardation is the reverse, where later contracts are cheaper, so rolling adds a boost (positive roll yield). The shape of the curve, not just the direction of oil, determines a futures fund's return.
What happened to oil ETFs in 2020?
When demand collapsed and storage filled in April 2020, front-month WTI futures briefly went negative for the first time ever. USO, holding those contracts, had to restructure into later-dated futures and absorb heavy roll losses in deep contango, so it failed to recover the way spot oil did. It became a textbook example of the risks of futures-based commodity funds.
What's a better way to invest in oil long term?
For most long-term investors, energy equity funds like XLE or VDE are cleaner. They hold the major oil and gas producers, whose profits move with crude, pay dividends, and avoid the roll-yield decay that erodes futures-based funds. Reserve futures-based oil ETFs for short-term trading, and only if you understand how contango affects them.
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Alex Harrington
CFA Level II Candidate, Finance & Economics
Alex Harrington is an independent ETF researcher and personal finance writer with over 8 years of experience analyzing exchange-traded funds. A CFA Level II candidate with a background in economics, Alex has reviewed 800+ ETFs and helped thousands of beginners build their first investment portfolios through clear, jargon-free education.
This content is for educational purposes only and does not constitute financial advice. Past performance does not guarantee future results. Consult a licensed financial advisor before making investment decisions.