June Chicago ethanol swaps, the biofuel additive to U.S. gasoline, rose 2.14% for the month, while coal for delivery in Rotterdam, the Netherlands, fell 10.59% in April as heating demand declines during spring. Meanwhile, June U.S. natural gas futures prices fell 7.95% as natural gas entered the shoulder season, when heating and cooling demand is low and tends to weigh on prices. European natural gas prices fell on seasonal fundamentals. U.K. natural gas futures prices for June delivery moved 10.70% lower i ...