In financial markets small pricing anomalies can arise which some traders like to exploit.
These are called arbitrage opportunities. For example, the same contract might briefly be priced slightly differently in two parts of the global market. A trader will buy the contract in the market where it is cheap and sell it where is pricier and take the difference as a small profit. As the gains available in this situation are usually tiny most arbitrageurs employ leverage (they borrow heavily) to magnify them.