The price of ethane returned to its mid-November level with a 15% bounce at Mount Belvieu, Texas, last week. At Conway, Kan., the 16.7% increase delivered ethane’s highest price since mid-August.

The leap contrasted with sagging prices for other NGL except for butane, which suffered a sharp decline.  Butane fell 9.5% at Mont Belvieu and 8.4% at Conway to its lowest point in four months at both hubs.

Ethane’s margin at Mont Belvieu, by Hart Energy’s calculations, more than doubled in the past week to an average above 5 cents per gallon (gal) for the first time since early December.