To the uninitiated, the "price of oil" seems like a single, static number. In reality, there is no such thing as one price for oil. There is the "spot price"—what you would pay to take delivery of a barrel right now—and then there are dozens of "futures prices" for delivery in one month, six months, or two years . A futures contract is a standardized agreement to buy or sell a specific asset on a particular date in the future . This section breaks down how these contracts work and why they are the primary way professionals trade commodities.

The Mechanics of the Trade: Standardized Agreements

A futures contract is a legal obligation. The buyer is obligated to take possession of the asset (or the cash equivalent) when the contract expires, and the seller is obligated to deliver it . Because these contracts are traded on major exchanges like the CME Group or the New York Mercantile Exchange (NYMEX), they are highly regulated and standardized .

Every contract specifies:

The Asset: e.g., Light Sweet Crude Oil.
The Quantity: e.g., 1,000 barrels.
The Quality: The "basis grade" .
The Expiration Date: The specific day the trade must be settled.
Settlement Method: Whether the physical "stuff" is delivered or if the parties just exchange the difference in cash .

The Two Players: Hedgers vs. Speculators

The futures market exists because two different groups of people have two different needs.

1. The Hedgers (The "Real World" Users)

Hedgers are the producers and consumers of the commodity. Their goal is not to make a "killing" in the market, but to eliminate uncertainty.

The Producer Example: A wheat farmer plants his crop in the spring. He is worried that by the time he harvests in the fall, the price of wheat will have crashed. To protect himself, he sells wheat futures contracts today. He has now "locked in" a guaranteed price, regardless of what happens to the market .
The Consumer Example: An airline knows it will need millions of gallons of jet fuel in six months. It fears a geopolitical crisis will spike oil prices. It buys oil futures today to lock in its costs and protect its profit margins .

2. The Speculators (The Liquidity Providers)

Speculators have no interest in wheat or oil. They are traders who aim to profit from price changes . They provide the "other side" of the trade for the hedgers. If a farmer wants to sell futures, a speculator might be the one to buy them, betting that the price will actually go up. Speculators make the market "liquid," meaning it is easy to buy and sell large volumes without moving the price too much .

The Three Sources of Return

When you invest in a commodity-linked ETF that uses futures, your return isn't just the change in the price of the commodity. It is actually the sum of three distinct components. Understanding this is vital for long-term investors.

Total Return = Spot Price Change + Roll Yield + Collateral Yield

Component 1: The Spot Price Change

This is the most intuitive part. If you "buy oil" at $80 and the price goes to $90, you have a $10 profit. This is the return from the actual movement in the market price for immediate delivery .

Component 2: The Roll Yield

This is where most beginners get tripped up. Because futures contracts expire, an ETF cannot just "hold" a contract forever. It must "roll" its position—selling the contract that is about to expire and buying a new one that expires further in the future .

If the new contract is cheaper than the one you sold, you get a positive roll yield (you can buy more of the commodity with the same money).
If the new contract is more expensive, you get a negative roll yield (you now own less of the commodity) .

Component 3: The Collateral Yield (Interest Income)

Futures are leveraged products. You don't have to pay the full value of the contract upfront; you only put down a small amount of "margin" or collateral. Commodity ETFs take the rest of the investors' cash and put it into safe, short-term interest-bearing securities like U.S. Treasury bills .

In the 1980s, when interest rates were in the double digits, this "collateral yield" provided huge returns even when commodity prices were flat .
In the low-rate environment following 2008, this yield was almost zero .

Comparison: Physical vs. Futures-Based Investing

Not all commodities are traded the same way. Some are easy to store, while others are impossible for the average person.

Commodity	Ease of Storage	Common Investment Method
Gold	High (Small, high value)	Physical Bullion or Physical ETFs (GLD)
Oil	Very Low (Bulky, dangerous)	Futures-linked ETFs (USO)
Wheat	Low (Perishable, bulky)	Futures-linked ETFs
Natural Gas	Extremely Low (Requires pipelines/tanks)	Futures-linked ETFs

Step-by-Step: How a "Roll" Works

Imagine an ETF that tracks crude oil. It is currently holding "Front-Month" contracts (the ones expiring soonest).

The Expiration Approaches: The current contract is set to expire in 5 days.
The Sale: The ETF sells its current contracts at the current market price (let's say $100/barrel) .
The Purchase: The ETF immediately buys "Next-Month" contracts.
The Price Gap: If the Next-Month price is $101, the ETF has to spend more to get the same exposure. It can now only afford 0.99 barrels for every 1.00 barrel it previously held. This 1% loss is the "roll cost" .
The Result: Over a year, a 1% monthly roll cost adds up to a nearly 13% drag on returns .