consists out of a premium or discount to the outright price
determined by various factors like the location and quality of a commodity
factor quality influences the basis (parties are generally willing to pay more or less depending on the commodity grade)
when a futures market is in contango, premiums tend to increase (parties start buying physical material to benefit from contango)
traders prefer to have the materials at locations where it can be delivered to the exchange or in regions where their off-takers are located (demand for material at a specific location can increase leading to a higher basis)
cannot always be hedged via futures
backwardations generally lead to weakening premiums, as it is more expensive to hold material
materials can be sold via forward sales contract that includes a fixed basis price (basis not exposed to price fluctuations)