In the oil industry, fuel oil is known as the bottom of the barrel. It’s typically cheap, unloved and, crucially, comes from the bottom of a petroleum-distillation tower — the tall piece of refining kit where crude gets heated and cracked into multiple petroleum products. But the Iran war has turned the industry upside down. Fuel oil is now an ultra-expensive commodity — and that’s bad news for the global economy.

Until now, the energy market has weathered the war shock reasonably well, with oil hovering at around $100 a barrel. But the situation with fuel oil is concerning, and it’s not receiving enough attention. Overshadowed by the other stuff coming higher up from the distillation process — diesel, jet fuel and, above all, gasoline — fuel oil plays a huge role in the modern world, powering the workhorses of globalization: container ships.

© Bloomberg