The price of crude oil slid again this week, falling by more than 5%. Oil is now down by more than 20% from its recent peak of $61 per barrel, as it has entered bear-market territory. The collapse in crude slammed oil stocks this week, with several slumping by double digits. According to S&P Capital IQ data, SandRidge Energy (NYSE:SD), Helix Energy Solutions (NYSE:HLX), and Ultra Petroluem (NASDAQ:UPL) were among the biggest energy movers this week.

That said, weak oil prices weren't the only catalyst behind these double-digit drubbings. Helix Energy Solution's stock plunge was more news-driven, as the company reported its second-quarter results this week. Unfortunately, the results were abysmal, as Helix Energy Solutions completely whiffed on estimates, reporting a loss when analysts were expecting a gain. 

SandRidge Energy's drop, on the other hand, was related to growing concerns investors have with the company as oil prices weaken. SandRidge Energy has an enormous pile of debt that some investors are betting will be its undoing.

Meanwhile, Ultra Petroleum's slump can be only partially attributed to oil. That's because Ultra Petroleum's stock was also hit by rising natural gas inventories and an analyst slashing the company's price target. With a lack of catalysts, investors see no reason to buy.

To learn more about why these catalysts caused the stocks to fall so sharply this week, check out the following slideshow. 

 

Matt DiLallo owns shares of SandRidge Energy. The Motley Fool recommends Ultra Petroleum. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.