Natty is a slang term for 'natural gas' or natural gas futures. Natural gas is among the most-volatile commodities, especially in contracts for prompt delivery. A big reason why is the demand for natural gas varies considerably based on the weather as it's primarily a heating fuel; though it's increasingly used in electricity production and that can also make it subject to swings on hot summer weather due to air conditioning demand. Increasingly, LNG demand also dictates the price of natural gas.
Natural gas is a fossil fuel composed primarily of methane, a chemical compound with the molecular formula CH4. It is found underground, often in association with deposits of oil, and is extracted through drilling. It is also used as a feedstock in the production of fertilizers and other industrial chemicals.