Reading the forward curve: contango, backwardation, and storage

A barrel has more than one price. There is the price for delivery this month, and there is the price for delivery in six months, and the gap between them is one of the most useful signals in the market. When the future is worth more than today, storage stops being a cost and becomes a trade.

The shape of the curve

Plot the price of Brent for every delivery month out to a year or two and you get the forward curve. It rarely runs flat. When later months trade above the prompt month the curve slopes upward, and we call that contango. When later months trade below the prompt month it slopes downward, and we call that backwardation. The shape is not decoration. It tells you whether the market is worried about supply today or worried about a glut tomorrow.

Take a simple case. If June Brent sits at 70 dollars and December Brent sits at 74, the four-dollar spread is the market offering to pay you for holding a barrel through the second half of the year. Whether that offer is worth taking depends entirely on what it costs you to hold it.

Contango and the storage play

Holding a barrel is not free. You pay tank rental, you pay to finance the cash tied up in the cargo, and you pay insurance. Add those together and you get the cost of carry. The storage trade is nothing more than a comparison: if the contango spread is wider than your cost of carry, you can buy the physical barrel now, sell it forward on the futures market, park it in a tank, and lock in the difference. The risk is largely taken off the table the moment both legs are done.

This is not a theory. In the spring of 2020, when demand collapsed and onshore tanks filled, the contango blew out so far that traders chartered supertankers purely to sit at anchor as floating storage. The spread paid for the ship and then some. That episode is the extreme version of a trade the market runs quietly every year.

• Cost of carry: tank rental, financing, and insurance, expressed as dollars per barrel per month.
• The signal: contango wider than carry means a positive storage margin is on offer.
• The lock: buy prompt, sell forward, and the spread is captured rather than gambled.

Contango pays you to wait, and backwardation pays you to hurry.

Backwardation and tight markets

Backwardation is the mirror image and usually the sign of a tight market. When buyers need barrels now, the prompt month is bid up above later months, so the curve slopes down. Here the incentive flips. Nobody is paid to store, because a barrel held today is worth more than the same barrel delivered later. The rational move is to sell prompt and draw down inventory rather than build it, which is why backwardated markets tend to run stocks lower and stay tight until fresh supply arrives.

For a trading desk, the curve also does quiet work behind the scenes. A backwardated market rewards the holder of a physical position through what is called roll yield, the gain from rolling a short-dated position forward into a cheaper contract. That mechanic, repeated month after month, is a real part of the return on carrying inventory.

What the curve is telling you

Read together, the two shapes are a running commentary on the balance between supply and demand. A curve tipping into contango is often the first hint of a building surplus, while a curve steepening into backwardation warns that the prompt market is short. Reading it well does not require a forecast. It requires understanding what the market is already paying you to do, and whether your cost of carry lets you take the offer.