The spot price is lower than the futures quotation or the contract price in recent months is lower than the forward contract price, which is called an active market. Forward market is also called normal market.

Reverse market, also known as reverse market or spot premium, means that under special circumstances, the spot price is higher than the futures price (or the contract price in recent months is higher than the contract price in forward months), and the basis is positive.

I don't know yet, just Baidu.