With oil prices plummeting over the past eight months, many energy companies have taken a hit, let's take a look at some energy companies TheStreet Quant Ratings says you should sell right now. The energy companies that explore, develop, and drill for oil have suffered the most from low oil prices. These companies' customers are bigger oil companies who hire them to explore for oil, but these giants, like ExxonMobil and ConocoPhillips, are reducing their capital expenditure spending due to the declining price of oil, and the slowly sinking-in realization that oil prices may not recover any time soon. Number 3 is Bill Barrett Corporation. With a 'D' rating, the company's flaws can be seen in its generally disappointing historical performance in the stock itself and weak operating cash flow. 2nd is, Atlas Resource Partners. This rating is a 'D.' Atlas Resource's shortcomings are in its deteriorating net income and disappointing return on equity. Number 1 is North Atlantic Drilling Limited. With an 'E+' rating the company's weaknesses can be seen in its weak operating cash flow and feeble growth in its earnings per share. TheStreet Ratings are algorithmic stock picks based on 32 major data points. S&P 500 stocks rated 'buy' yielded a 16.5% return in 2014, beating the S&P 500 Total Return Index by more than 300 basis points. For the full reports on these stocks, you can check out TheStreet.com/QuantRatings.