Basis (Futures)
In futures markets, basis is the difference between the spot (cash) price of an asset and the price of a corresponding futures contract, representing the cost of carry and any supply-demand imbalances between immediate and forward delivery.
Basis is a foundational concept in futures pricing and hedging. The standard formula is: Basis = Spot Price minus Futures Price. When the spot price is below the futures price (as is typical in contango markets), basis is negative. When the spot price is above the futures price (as in backwardation), basis is positive. The magnitude and direction of basis reflect the net cost of carrying the underlying asset forward in time.
For financial futures on equity indexes, the theoretical basis is determined by the cost-of-carry model: the futures price should equal the spot price plus financing costs minus dividends received over the contract period. Any deviation from this theoretical value creates an arbitrage opportunity exploited by program traders — large institutions that simultaneously buy the cheaper side and sell the more expensive side to lock in a riskless profit, driving basis back toward fair value.
For commodity futures, basis incorporates storage costs, transportation costs, and local supply-demand conditions. A grain farmer who sells wheat futures to hedge a crop understands that the futures price they lock in may differ from the local cash price they receive at harvest. This basis risk — the possibility that the relationship between spot and futures prices will change — is an inherent but manageable risk in most commodity hedging programs.
Basis risk is why futures hedges are rarely perfect. If an oil producer hedges with CME WTI crude futures but sells physical crude at a refinery in Houston, the local basis between NYMEX WTI and Houston cash crude can move independently of the futures price, introducing residual risk even in a fully hedged position. Managing basis risk requires understanding local market dynamics in addition to the futures market itself.
Traders who actively trade basis — buying the spot and selling futures, or vice versa — are called basis traders or cash-and-carry traders. These participants play a vital role in keeping futures prices aligned with fair value and ensuring that hedgers can execute their programs at economically rational prices.