The share price of Hallador Energy Company (NASDAQ:HNRG) surged by 11.78% between December 5 and December 12, 2025, putting it among the Energy Stocks that Gained the Most This Week. Hallador Energy (HNRG) - Among the Energy Stocks that Gained This Week Hallador Energy Company (NASDAQ:HNRG), through its subsidiaries, engages in the production of steam coal for the electric power generation industry in Indiana. The company has now evolved into a growing, vertically integrated Independent Power Producer (I ...