Global refineries produce around 9 million barrels of residual fuel oil every day as a by-product of the refining process.
Around 4 million barrels of this is traded freely on the open market.
New refineries and upgrades to existing refineries are producing less fuel oil. Currently, fuel oil is cheap and plentiful, but in time, the supply constraints, fuel standards, and lower carbon requirements will impact prices.
With the new lower sulfur fuel standards that came into effect in 2015 (and again in 2020), power plants, shipping companies, and other industrial burners will struggle to meet these standards while keeping fuel cost down. These changes could potentially have a profound impact on the global economy.