Basis refers to the difference between the spot price of a specific commodity at a specific time and place and the futures price of that commodity in the futures market.

Namely: basis = spot price-futures price. Different reference objects have different basis difference results.

For example, if the wheat spot price in July 1 is 800 cents/bushel, the wheat futures contract price in September is 8 10 cents/bushel, and the wheat futures contract price in October 10 is 830 cents/bushel.

Basis = wheat spot price (800)- wheat futures price (8 10)=- 10.