For decades, Europe relied on a tried-and-tested way to ensure there was enough gas to get through winter: Traders bought when the fuel was cheaper in the summer, stored it and then sold at a higher price when needed.

But for the second year in a row, the economics of that trade have unraveled.

The loss of steady year-round Russian pipeline gas following the war in Ukraine means Europe has become more reliant on global liquefied natural gas (LNG) supplies — and fears about a tight LNG market in 2025 made European summer prices more expensive at times. It has been a similar story this year, made even worse by the Iran conflict that has choked off crucial supplies from the Middle East.