Oil is one of the most traded commodities and known around the world. After all oil is an excellent raw material, but at the moment it is our greatest source of energy, mainly for transport.
Oil just as Forex and Gold can be operated 24 hours a day and has excellent liquidity and volatility. Oil is a commodity very politically influenced as among the major producers are unstable regimes or they are located in unstable areas like the Midwest.
As one of the main sources of energy current oil prices directly influences inflation rates around the world.