What it means
The word "basis" here means the difference between the price of the item you actually buy or sell and the price of the contract you use to hedge it. If both prices move by the same amount, the basis stays constant and the hedge works perfectly.
Basis risk is simply the risk that this difference changes while your hedge is running. Perfect hedges are rare because liquid contracts exist for a limited menu of standard commodities, currencies and interest rates.
An airline can trade crude oil futures but not futures on jet fuel delivered to its specific airport, so it accepts a cousin contract and lives with the gap. The same problem appears with grades, locations and delivery dates that do not quite match.
This matters because finance teams often report a hedge as if it eliminates risk entirely. It does not: it converts a large, unpredictable price risk into a much smaller basis risk, which is a genuine improvement but not the same as certainty.
Boards that fail to grasp the distinction are surprised when a fully hedged position still produces a loss. Basis risk also shows up in interest rate management, where a business borrows against one floating reference rate and hedges with a swap linked to another.
The two rates usually track each other closely, and then in stressed markets they do not. Anyone who lived through a reference rate transition will recognise how expensive that divergence can become.
The sensible response is measurement rather than despair. Compare the historic relationship between your exposure and the proposed hedge, size the typical drift, and decide whether the residual is small enough to accept before you place the trade.
In practice
Real-world examples.
Example
A copper cable manufacturer hedges its metal purchases with exchange traded copper futures, but buys a specific alloy whose premium over standard copper rises during a supply squeeze. The futures gain offsets most of the increase, and the widened premium leaves a shortfall on the purchase ledger.
Example
A property developer borrows on a facility linked to one floating rate and hedges with a swap referencing a different one. For two years the two rates move within a few basis points of each other, then a credit scare pushes them apart and the developer pays more interest than the swap refunds.
Example
A grain trader in one region hedges using futures that settle against delivery at a distant hub. A local harvest glut depresses prices at home while the hub price holds firm, so the hedge overcompensates and the trader books an unexpected profit rather than a neutral result.
Think of it
“Basis risk is the danger that your hedge isn't perfect-spot and futures don't match exactly.
Formula
Calculation
Basis = spot price of the asset being hedged - price of the hedging instrument
Change in basis = closing basis - opening basis
A regional airline expects to buy 2,000,000 gallons of jet fuel in six months. Jet fuel currently costs $2.40 a gallon, and the airline hedges using crude oil futures that are equivalent to $2.10 a gallon. The opening basis is $2.40 - $2.10 = $0.30 a gallon.
Six months later jet fuel has risen to $3.00 a gallon and the crude futures position is worth $2.55 a gallon, so the closing basis is $3.00 - $2.55 = $0.45. The physical fuel now costs $0.60 more per gallon, or 2,000,000 x $0.60 = $1,200,000 extra. The futures position gains $0.45 a gallon, or 2,000,000 x $0.45 = $900,000.
The hedge therefore covers $900,000 of a $1,200,000 cost increase, leaving $300,000 unprotected. That $300,000 is exactly the $0.15 widening of the basis multiplied by 2,000,000 gallons, and it is the whole of the airline's basis risk made visible.Case study
Seen in the real world.
This case is illustrative and the company is fictional. Meridian Coach Lines, an invented long distance bus operator, hedged 80% of its expected diesel purchases using crude oil futures and told its lenders that fuel cost was under control. For three years the arrangement behaved well and management stopped examining it.
In the fourth year a refinery outage pushed diesel prices sharply above crude, widening the basis by around $0.20 a gallon. Meridian's hedge produced the gain it always had, yet the fictional company's fuel bill still overshot budget by roughly $1,100,000, and the finance director had to explain a variance on a line item the board believed was fixed.
The response was not to abandon hedging but to measure it properly. Meridian began reporting hedged fuel cost as a range rather than a single number, sized on five years of observed basis movement, which meant future variances landed inside a band the board had already seen and approved.
Watch out
Common mistakes.
- Describing a position as fully hedged when the hedging instrument is only a proxy for the real exposure.
- Ignoring differences in delivery location, grade or timing, which are the three most common sources of basis drift.
- Assuming a historically stable basis will stay stable, when basis relationships tend to break exactly when markets are stressed.
Questions
People also ask.
Is basis risk always bad for the hedger?
No, the basis can move in your favour and produce a small windfall, but the point is that the outcome is uncertain rather than reliably positive.
How do I reduce basis risk?
Choose a hedging instrument that matches your exposure as closely as possible on product, location and date, or negotiate a customised over-the-counter contract and accept the higher cost.
Does basis risk apply outside commodities?
Yes, it is common in interest rate hedging, currency hedging with a proxy currency, and equity hedging where an index is used to protect a portfolio that does not match it.
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