Under normal circumstances, 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 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.

There are many reasons for this. Usually, it is a positive market, that is, the futures price is usually higher than the spot price, because the futures price includes the position fee. However, when the supply is insufficient and the demand is strong, investors will also buy crazily. At this time, the spot price is higher than the futures price, forming a reverse market.

It is also necessary to judge the future price for arbitrage. Not all arbitrage will be profitable and there will be risks.

Sorry, I don't have any information about cases and books. I think there will be some online. I hope you can teach me when you successfully learn this knowledge:)