Gas traders pleaded for cash as Texas cold upended their market

The urgent phone calls came over the holiday weekend: traders of natural gas needed more money, and fast.

Temperatures were starting to plummet across the central U.S. Prices for the heating fuel had skyrocketed 300-fold to levels nobody had thought possible. This would later prove to be the precursor of one of the worst energy crises the nation had seen, plunging millions into darkness for days amid a deadly deep freeze.

But on Saturday, traders in the relatively small and obscure world that is the physical gas market were singularly focused on one very big problem: exchanges were demanding more collateral because of the volatility. The traders had until Tuesday to come up with the cash or else they’d be forced to exit their positions and, in some cases, face potentially catastrophic losses.