Basis Risk

A farmer hedges crop risk by shorting futures. But they face a new risk: what if the basis between spot and futures moves against them? This is basis risk—the risk that the hedge itself backfires.

What basis risk is

The basis is the difference between spot and futures prices. For corn, if spot is $5.00 and December futures are $5.20, the basis is -$0.20 (futures are $0.20 higher).

A farmer hedging plans: “I’ll short December futures at $5.20. At harvest in October, I’ll sell my corn at spot and buy back the futures to close my short. The basis will lock in my revenue.”

But basis is not constant. It depends on storage costs, interest rates, convenience yields, and supply-demand expectations. As the contract approaches expiration, basis typically converges to zero (futures price equals spot). But between now and December, the basis can widen or narrow unexpectedly.

Basis risk: The risk that the basis moves adversely, leaving the hedger worse off.

Example:

Farmer shorts Dec futures at $5.20 when spot is $5.00 (basis = -0.20).
In October, spot corn is $4.80 (down 4%), but Dec futures close at $5.10 (down 2%).
New basis is -0.30 (worse for the farmer).
The farmer sells spot at $4.80 and covers the short at $5.10, locking in -$0.30 hedging loss plus the spot price.
Revenue is $4.80 - ($5.10 - $5.20) = $4.90. But without hedging, revenue would have been $4.80. The hedge made them worse off by $0.10.

The farmer intended to lock in $5.20; instead, they locked in $4.90 because the basis widened against them.

Why basis changes

The basis reflects cost of carry: storage, interest to finance inventory, and convenience yield (the value of holding the physical).

Storage costs shift: Early season, when storage is empty, the basis is typically tight (futures close to spot). As harvest approaches and warehouses fill, storage costs rise, widening the basis.

Interest rates shift: If the Fed cuts rates, financing inventory becomes cheaper, narrowing the basis. If rates rise, storage becomes more expensive, widening it.

Convenience yields shift: In tight supply years, holding physical inventory has high value (you can sell high-quality inventory at a premium). Convenience yield widens the basis. In abundant supply years, inventory is worthless; convenience yield falls, basis tightens.

Supply and demand expectations shift: A crop report showing abundance will compress the basis (the market expects more supply, making physical less valuable). A geopolitical shock that threatens supplies will widen the basis (physical becomes more precious).

Location and grade basis risk

Farmers do not all face the same basis. A farmer in Nebraska shipping to an Illinois elevator faces different logistics costs than a farmer in Iowa shipping locally.

The futures contract specifies delivery location(s). If the farmer is 500 miles from the nearest approved delivery point, they must transport their corn to deliver futures, creating a location-specific [basis](/wiki/basis/].

Similarly, if the futures contract permits only “contract grade” corn (certain moisture, test weight, kernel uniformity), a farmer with slightly off-spec corn faces basis risk: they must either downgrade or accept a lower spot price than futures, widening their basis.

Hedging with basis risk

Sophisticated hedgers manage basis risk by understanding it:

Historical basis analysis: A farmer might study historical basis patterns for their location. “Over 10 years, Dec corn basis in my county averages -0.25, with a standard deviation of 0.10.” This gives them a sense of expected basis and uncertainty.
Partial hedges: Instead of shorting futures equal to 100% of production, a farmer might short 70%, leaving 30% unhedged. This reduces basis risk (the unhedged portion benefits from favorable basis moves) while still capturing directional protection.
Cross-hedging: If a direct hedge does not exist, a farmer might hedge with a related contract. A farmer hedging beef might use live cattle futures (not a perfect match), accepting cross-hedge risk (the correlation between beef and cattle futures might break down).
Roll timing: A farmer planning to harvest in October but hedging December futures accepts a 2-month basis risk. A savvy farmer might shift to selling spot in a forward contract with a local elevator instead, accepting only the immediate basis (which is tighter because the transaction is imminent).

Basis risk in energy and metals

Basis risk extends beyond agriculture. An airline hedging fuel costs with heating oil futures faces basis risk: actual jet fuel prices move differently than heating oil futures.

A copper mining company hedging production with copper futures faces location basis risk (their mines are in Peru; futures are based on LME deliveries in London). They also face grade basis risk: their ore produces 99.9% pure copper, while futures assume 99.5% purity. The premium for higher purity can widen or narrow, creating basis risk even if futures prices are locked in.

Basis convergence at expiration

One certainty: as a futures contract nears expiration, basis converges toward zero (the futures price equals spot, or equals delivery price if physical settlement). An arbitrageur can lock this in: buy spot, store, and deliver via [futures](/wiki/futures-contract/], earning the remaining basis as profit.

This convergence means basis risk is transient. A wide basis is a temporary phenomenon. The question is: when do you need to settle? If you settle before convergence, you bear basis risk. If you settle at expiration, basis risk is eliminated.

The paradox: hedging creates new risk

Basis risk illustrates a core truth of hedging: eliminating one risk often creates another.

Without a hedge: You face directional price risk (corn price falls 20%, you lose 20%). No basis risk.
With a hedge: You face basis risk (the basis widens, your hedge loses money). Directional risk is reduced but replaced.

The goal of hedging is to trade a large, scary directional risk for a smaller, more manageable basis risk. If the hedge works as designed, basis risk is the “noise”—a small residual uncertainty—while the directional move is captured.

But if basis behaves unexpectedly (correlation breaks down, logistics shift, supply shocks), the hedge can fail, leaving you worse off than if you had gone unhedged.