The price of crude oil jumped this week, heading from $45 per barrel to more than $50 a barrel at one point. This fueled strong gains among oil stocks; however, according to S&P Capital IQ data, the best gains were made by Penn West Petroleum (NYSE: PWE), Energy XXI (NASDAQ: EXXI), and Stone Energy (NYSE: SGY).
While higher oil prices were the main fuel behind this week's rally, it wasn't the only catalyst. Stone Energy's surge likely had more to do with short covering than bullish buying. That's because more than 27% of Stone Energy's shares were sold short due to concerns about its debt, with those concerns easing as oil heads higher.
Short covering was also likely the main fuel behind the wicked rally in Energy XXI this week, too. That's because Energy XXI's other news, a credit downgrade and the announcement of a $500 million shelf registration, aren't exactly bullish catalysts.
Penn West Petroleum's surge, on the other hand, was due to some M&A news. The company announced its second non-core asset sale in a month, which will give it more cash to pay down debt. In addition to that, Penn West was mentioned as a potential acquisition target itself after a major acquisition was announced in the Canadian energy sector.
To learn even more about this week's big movers, check out the following slideshow.