Basis is an index to measure cotton price fluctuation, which refers to the difference between futures price and actual spot price. The change of basis is usually caused by market supply and demand, transportation cost, quality and season. When the market supply and demand are unbalanced, the basis will expand, and vice versa. Therefore, when buying and selling cotton, it is particularly important to understand the change of basis, which can help buyers and sellers make more informed decisions.

The fluctuation of cotton basis also affects the livelihood of cotton farmers. Because the foundation of cotton changes greatly, it often leads to the increase or decrease of cotton farmers' income. If the basis difference is large, it means that there is a big difference between the spot price and the futures price, and cotton farmers can get higher prices when selling cotton. On the contrary, if the basis is small or negative, cotton farmers may face the risk of loss.

At the same time, the basis difference also has an important impact on the operation of the whole cotton spinning industry. As an important raw material for textile enterprises, the price fluctuation of cotton will directly affect the production cost and market demand of textiles. Some large textile enterprises will control the cotton import and futures market by manipulating the basis to maintain their competitiveness. Therefore, the change of cotton basis is not only a simple price issue, but also involves the operation and adjustment of cotton industry chain.