This was another busy week for the market, with earnings season overflowing a seemingly unending torrent of news to digest. That earnings news was a key fuel behind the biggest stock moves in the energy sector. The biggest movers, according to S&P Capital IQ data, were Northern Tier Energy (UNKNOWN:NTI.DL), CONSOL Energy (NYSE:CNX), and Peabody Energy (NYSE:BTU)

Weak earnings reports sent both CONSOL Energy and Peabody Energy plunging this week. Both companies lost money this quarter, with CONSOL turning in a much worse than expected loss of $0.28 per share, while Peabody Energy lost $8.13 per share. CONSOL was affected by weakness in both the coal and natural gas markets, with it growing even more bearish on coal. Peabody Energy, likewise, is now anticipating additional weakness in the coal market. Further, one of its rivals announced the termination of a debt swap deal that would have staved off bankruptcy. With Peabody having reportedly been considering a similar deal, its outlook is beginning to look bleak. 

While I said earnings was one of the key fuels behind this week's biggest movers, it wasn't the only fuel. A buyout offer sent units of Northern Tier Energy soaring this week after Western Refining (NYSE:WNR) offered to buy the company for $2.5 billion. It is a move that makes a lot of sense considering that Western Refining already owns 38% of Northern Tier as well as 100% of its general partner. That preexisting ownership relationship certainly gives Western Refining a leg up against any competing offers. 

To learn even more about why these stocks moved so sharply this week, check out the following slideshow.