China’s near-50% leap in LNG imports this year has surprised many in the industry. With aggressive buying as winter approaches, spot prices in northeast Asia have jumped to near $10/mn BTU in recent weeks, their highest level since early 2015.

Soaring Chinese imports have been driven by Beijing’s coal-to-gas switching policy. With demand far outstripping volumes under long-term contracts, Chinese buyers have turned to flexible short-term volumes, including from the world’s...