Sources of basis risk
Quality mismatch: a corn farmer hedging with CBOT corn futures might grow a grade of corn that commands a different premium or discount to the exchange’s benchmark grade. If her corn is lower quality than the standard, it will price at a discount — and that discount could widen. Location mismatch: jet fuel prices in London are correlated with crude oil futures in New York, but not perfectly — transport costs, local refinery capacity, and regional supply create a spread that fluctuates. Airlines hedging jet fuel with crude oil futures retain the refining spread risk as basis risk. Timing mismatch: futures contracts expire on specific dates. If the underlying transaction occurs between expiry dates, the hedge must be rolled forward, and the roll involves paying (or receiving) the forward basis — which can move adversely. Credit basis: in credit markets, a bond issuer’s credit spread and the CDS spread on the same issuer should be equal (by the CDS-bond basis arbitrage) — but in stress periods they diverge significantly, leaving hedgers exposed to basis moves even when credit risk itself is hedged.
When hedges fail spectacularly: the MGRM case
Metallgesellschaft Refining & Marketing (MGRM) is the canonical case study in basis risk and hedge failure. MGRM sold long-term fixed-price oil contracts to customers (effectively short oil exposure over 10 years) and hedged by buying short-dated oil futures, rolling them forward monthly. The strategy assumed that the roll would be approximately cash-neutral — based on historical contango/backwardation patterns. In 1993, oil markets moved into deep contango (futures prices higher than spot), meaning each monthly roll required MGRM to sell cheaply and buy expensively. The cash losses from rolling futures were real and immediate; the offsetting gains from the long-term customer contracts were unrealised and spread over years. The funding crisis forced MGRM to close the position at a loss of approximately $1.3 billion — a hedge that became a catastrophe because basis risk and cash flow timing were not managed.
“A hedge is not a risk elimination — it is a risk transformation. You trade the original risk for basis risk, liquidity risk, and counterparty risk. The question is whether the transformed risks are smaller and more manageable.”
What this means for you
The existence of basis risk does not mean hedging is futile — it means hedging reduces but does not eliminate risk, and the residual basis risk must be measured and managed. The practical implications: choose hedging instruments that are as closely correlated with the underlying exposure as possible; understand the sources of divergence in advance; monitor the basis and have a plan for when it widens; and manage the cash flow implications of futures hedges (margin calls can be larger and faster than the underlying gain). A hedge that looks perfect on paper can fail if the underlying and hedging instrument respond differently to the specific shock you encounter — basis risk is largest precisely in the crisis scenarios where hedging matters most.