Basis is a unique concept of spot minus futures, which 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. This difference reflects the price difference between the spot market and the futures market, as well as the changes in market supply and demand, market sentiment and market trend.

The calculation formula of basis is: basis = spot price-futures price. This formula is simple and clear. By comparing the spot price with the futures price, the basis can be obtained. The change of basis is one of the important indicators that investors need to pay attention to. If the basis continues to expand, it shows that the market is on the rise, because the futures price is higher than the spot price, and investors can buy futures contracts for speculation.