The coronavirus pandemic is hurting the world economy in some extreme ways. One of the most extreme is the distortion affecting the US market for oil. On Monday the price of American crude fell below zero for the first time in history. The reason for the one-day collapse was in part technical; amid a plunge in demand, an important one-month futures contract expired the following day. With storage running low, traders holding the derivative contract found themselves with nowhere to put the oil. The owners of supertankers are among the surprise winners of the crisis — day rates to hire the vessels and their oil tanks have jumped fivefold.

The historic low is the clearest sign yet of the depth of the economic damage being done by state-imposed lockdowns to counter the spread of the virus. Demand for oil has been cut by up to a third worldwide. Oversupply has only exacerbated the situation. The price of Brent crude, the international benchmark, dropped below $20 on Tuesday for the first time in 18 years.

The price collapse makes a mockery of President Donald Trump’s claim a week ago that he had managed to put a floor under the price after securing a deal between Saudi Arabia and Russia to cut production from next month. The deal has proven to be too little, too late. It has underlined the miscalculation by both Russia and Saudi Arabia in pursuing a price war at a time of extraordinary economic weakness. There are valid questions over how long Russia’s economy can withstand a sustained period of low oil prices.