The Oil and Gas Operations sector (DIG) is down 0.5%, underperforming the market overall. The current biggest movers in the sector are:

Company | Market Cap | Percentage Change |

Southwestern Energy (NYSE:SWN) | $11.52 billion | +3.4% |

Energy XXI (Bermuda) Limited (Nasdaq:EXXI) | $2.64 billion | -3.2% |

Range Resources Corp. (NYSE:RRC) | $10.19 billion | +3% |

Sandridge Mississippian Trust I (NYSE:SDT) | $758.5 million | +2.4% |

Whiting Petroleum Corporation (NYSE:WLL) | $4.97 billion | -2.3% |

Plains Exploration & Production Company (NYSE:PXP) | $5.37 billion | -2.2% |

Cenovus Energy Inc (USA) (NYSE:CVE) | $23.71 billion | -1.7% |

**Software Summary: Finviz.com Stock Screener**

**Southwestern Energy**(NYSE:SWN) has risen 3.4% and is currently trading at $34.13 per share. The company's volume for the day so far is 2.8 million shares, in keeping with the average volume over the past three months. As a stock moves up or down, it is important to pay attention to the trading volume. This indicates the level of interest: the higher the volume, the more the interest. Looking at a company's valuation ratios is a good way of getting a basic idea as to its value as an investment. There are generally two price/earnings ratios calculated: the first, called the trailing Price/Earnings ratio, is calculated using the previous years actual earnings; the second, called forward Price/Earnings ratio, is calculated using the next year's estimated earnings. SWN has a P/E ratio of 19.0, high compared to the industry average of 16.87. This could mean that the market is expecting big things over the next few months or years. High P/E stocks could be "growth" stocks, while low PE stocks may be "value" stocks. SEE: How To Use The P/E Ratio And PEG To Tell The Future Of A Stock

Currently trading at $32.41 per share,

**Energy**(Nasdaq:EXXI) has fallen 3.2%. This morning, the company is trading a volume of 365,025 shares. High volume indicates a lot of investor interest while low volume indicates the opposite. Valuation ratios like the price to earnings (P/E) ratio, the price to earnings growth (PEG) ratio, the price to sales (P/S) ratio, the price to book (P/B) ratio, and the dividend yield are useful in determining how attractive a potential or existing investment is. The price/book value ratio, often expressed simply as "price-to-book", provides investors a way to compare the market value, or what they are paying for each share, to a conservative measure of the value of the firm. The P/B ratio for EXXI is 2.03, indicating that the stock is trading for more than its book value. This may be a sign that the company is overvalued. All else being equal, a stock with a low P/B value ratio is more attractive than a stock with a high ratio. SEE: Investment Valuation Ratios: Price/Book Value Ratio

**Range**(NYSE:RRC) is currently trading at $64.56 per share, a 3% increase. The company's volume is currently 1.9 million shares for the day, which is more trading activity than there was yesterday. Volume is an important indicator in technical analysis as it is used to measure the worth of a market move. If the markets have made a strong price move either up or down the perceived strength of that move depends on the volume for that period. The higher the volume during that price move the more significant the move. Investors can make use of valuation ratios to estimate whether a stock is fairly valued. The dividend yield is measured by taking the annual dividends per share and dividing that number by the stock price. RRC's dividend yield of 0.3% is fairly low. A company with a low dividend yield may be a safer investment in the long run. To calculate the dividend yield, divide the level of dividends by the stock price; the higher the yield, the more attractive the security. SEE: Due Diligence On Dividends

**Sandridge Mississippian Trust**(NYSE:SDT) is up 2.4% to reach a current price of $27.73 per share. So far today, the company's volume is 56,009 shares. This is 0.3 times its current daily average. When a stock price moves up or down, watching the volume is a good way of identifying how significant that shift is. It is important for an investor to estimate the value of any potential or existing investment; valuation ratios make this easier. Perhaps one of the most widely-used stock analysis tools is the price-to-earnings ratio, or P/E. SDT's P/E ratio of 14.4 is above the industry average of 9.34. Generally speaking, the higher the P/E ratio, the higher the market expectations for a company's future performance. A high P/E ratio indicates a stock that is expensive, while a low P/E ratio indicates a stock that is cheap. SEE: How To Find P/E And PEG Ratios

**Whiting**(NYSE:WLL) has fallen 2.3% and is currently trading at $41.25 per share. With 595,530 shares changing hands so far today, the company's volume is 0.3 times the average volume over the last three months. Volume is an important indicator in technical analysis as it is used to measure the worth of a market move. If the markets have made a strong price move either up or down the perceived strength of that move depends on the volume for that period. The higher the volume during that price move the more significant the move. Valuation ratios include the price to earnings (P/E) ratio, the price to earnings growth (PEG) ratio, the price to sales (P/S) ratio, the price to book (P/B) ratio, and the dividend yield. The assumption with high price/earnings stocks (generally of the growth variety) is that investors are willing to buy at a high price because they believe that the stock has significant growth potential, and the price/earnings to growth (PEG) ratio helps investors determine the degree of reliability of that growth assumption. WLL's PEG ratio is 0.9. Because of the adjustment for earnings growth rate, the PEG ratio is somewhat more useful than many formulas for comparing companies in different industries.

**Plains Exploration & Production**(NYSE:PXP) is down 2.2% to reach $40.71 per share. So far today, the company's volume is 518,962 shares. If a stock is trading on low volume, then there is not much interest in the stock. On the other hand, if a stock is trading on high volume, then there is a lot of interest in the stock. Investors can use valuation ratios as tools to estimate what kind of deal a particular investment is. The price/book value ratio is calculated by dividing the current stock price by the company's book value per share. PXP's stock is trading for more than its book value with a P/B ratio of 1.7. It is important to take the company's debt into account when using the P/B ratio as debt can boost a company's liabilities to the point where they wipe out much of the book value of its hard assets, creating artificially high P/B values. One problem with the P/B value ratio is that it can be difficult to calculate the true book value of a company, so investors should be aware that many measures of book value may provide only a rough estimate, and should be taken with a grain of salt. SEE: Using The Price-To-Book Ratio To Evaluate Companies

After a decline of 1.7%,

**Cenovus Energy Inc**(NYSE:CVE) has hit a share price of $30.89. So far today, 470,875 shares have changed hands, lighter than yesterday's volume of 1.8 million shares. In technical analysis, trading volume is used to determine the strength of a market indicator. When estimating the value of a particular investment, valuation ratios provide a good basis for assessing the value of an individual stock. For investors primarily interested in the income a stock can generate, the dividend yield is an important determinant of how attractive a stock is. CVE's dividend yield is 2.8%. It is important to remember that while a higher dividend yield is more attractive, all else being equal, a higher dividend yield can also indicate greater perceived risk. SEE: Dividend Yield For The Downturn

**The Bottom Line**On any given day, a particular stock may see positive or negative change in its share price. Paying close attention to the previous ratios will help you identify key times to adjust your strategy. Keep in mind that all these ratios should be compared against historical numbers and industry information in order to get a more complete picture.