Crude oil futures are the most important oil futures varieties, which are uniformly formulated by futures exchanges and standardized contracts with crude oil as the target. There are four important crude oil futures contracts in the world: the New York Mercantile Exchange (NYMEX) light and low-sulfur crude oil, namely "West Texas Intermediate" futures contract, high-sulfur crude oil futures contract, London International Petroleum Exchange (IPE) Brent crude oil futures contract and Singapore Exchange (SGX) Dubai acid crude oil futures contract.