GC Newcastle coal futures tumbled by over 30% to $150 per metric ton, the lowest in three months, and are more than 40% below a record high of $269.5 hit on October 5th, as China stepped up policies to boost output ahead of the winter season. China’s average daily output increased by over 1.2 million tonnes to a record at above 11.6 million tonnes on October 18th. As a result, Chinese power plants now have stocks to produce power for 16 days from less than two days’ inventories at the start of October.