On the week of February 15, 2021, futures prices for electricity on Texas’s power grid increased by 12,000%, to the price cap of $9,000 per megawatt hour. The state had been hit by a huge snowstorm which wiped out its energy capacity, as snow blocked solar panels and sub-zero temperatures froze wind turbines and natural gas wells.

“This was just through the roof,” said the head of risk at one clearing firm at the time. “This is one to look at and say: ‘What’s going down here? Is this really