Crude oil futures contracts are time-limited. Before the expiration of the contract, the warehouse receipt held by the dealer should be closed as required, otherwise it will easily lead to forced liquidation. The time limit for traders to hold fixed contracts is not long, especially when there are many main contracts for traders to trade.

Crude oil futures contracts are constantly changing. When one contract expires, another futures contract will be listed accordingly. Traders can trade this futures product continuously, but the contract month has changed.