The gut-wrenching volatility continued in the energy sector this week after oil prices bounced around quite a bit, but remained in the low-$30-a-barrel range. That low price, along with a bevy of company-specific news items. weighed heavily on energy stocks this week. Five of the worst performers were, according to S&P Capital IQ data, National Oilwell Varco (NYSE:NOV), Oceaneering International (NYSE:OII), Capital Product Partners (NASDAQ:CPLP), Ardmore Shipping (NYSE:ASC), and Marathon Petroleum (NYSE:MPC)

Earnings were the big catalyst moving energy stocks, with National Oilwell Varco, Ardmore Shipping, and Marathon Petroleum all moving lower after reporting. All three missed estimates due to the continued weakness in the oil and gas market. Their outlook also wasn't much better, with National Oilwell Varco expecting things to get even worse in the first quarter of 2016. Meanwhile, Marathon Petroleum had to tone down distribution growth at its MLP because of market weakness. 

The other two names on this list, Oceaneering International and Capital Products Partners, moved lower after updating investors on their respective fleets. Oceaneering International announced that one of its contracts would be terminated six months early, while Capital Products Partners actually was able to find new contracts for two of its vessels; however, the timing and term didn't sit well with investors. 

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

Energy Stocks Plunge Again This Week from The Motley Fool.

Matt DiLallo owns shares of National Oilwell Varco. The Motley Fool owns shares of and recommends National Oilwell Varco. The Motley Fool recommends Oceaneering International. 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.