Mild autumn weather is allowing domestic natural-gas stockpiles to build before furnaces get fired up, allaying fears of winter shortages and sending prices on big day-to-day swings.
Natural-gas futures for December delivery closed 5.5% higher at $5.149 per million British thermal units on Thursday. It was the 13th time over the last 34 trading days that prices moved more than 5% up or down. Two days earlier the price went as low as $4.91. Two weeks before that it was $6.22.