It's been a good morning for the market. The Nasdaq has risen 0.6%; the S&P 500 has climbed 0.5%; and the Dow has moved up 0.6%.

Underperforming the market overall, the Oil and Gas Operations sector (DIG) is up 0.4%, and these are its current biggest movers:

Company Market Cap Percentage Change
QEP Resources (NYSE:QEP) $4.83 billion +6.9%
Calumet Specialty Products Partners (Nasdaq:CLMT) $1.55 billion +2.8%
Delek US Holdings (NYSE:DK) $1.48 billion -2.6%
Permian Basin (NYSE:PBT) $834.3 million -2.6%
Sandridge Mississippian Trust (NYSE:SDT) $693.3 million +2.4%
Oasis Petroleum (NYSE:OAS) $2.7 billion +2.2%
Cabot Oil & Gas (NYSE:COG) $8.53 billion +2.1%

Broker Summary: TD Ameritrade Thinkorswim

QEP Resources (NYSE:QEP) is at $29.05 per share after an increase of 6.9%. So far today, the company's volume is 2.8 million shares, 1.4 times the current daily average. Volume is also used as a secondary indicator to help confirm what the price movement is suggesting. Investors can make use of valuation ratios to estimate whether a stock is fairly valued. The capitalization ratio measures the debt component of the capital structure, or capitalization of a company (i.e., the sum of long-term debt liabilities and shareholder equity) to support operations and growth. The capitalization ratio for QEP is 35.7%. A low level of debt and a healthy proportion of equity in a company's capital structure is an indication of financial fitness.

Calumet Specialty Products Partners (Nasdaq:CLMT) is up 2.8% to reach a current price of $27.77 per share. The company's volume for the day so far is 251,132 shares. High volume indicates a lot of investor interest while low volume indicates the opposite. Valuation ratios allow the investor to make a quick determination as to a company's investment value. A company's price/earnings ratio (P/E ratio) provides a measure of how expensive or cheap a stock is. CLMT's P/E ratio of 8.0 falls below the industry average of 15.49. Companies with low P/E ratios may find it easier to surprise the market to the upside, even if their financial performance is not as strong as that of companies with high P/E ratios. A high or low P/E ratio is not good or bad in and of itself, but a company trading with a high P/E ratio must continue to post strong financial performance or its stock price is likely to fall. SEE: How To Use The P/E Ratio And PEG To Tell The Future Of A Stock

Delek US Holdings (NYSE:DK) is trading at $24.66 per share, down 2.6%. So far today, 209,874 shares have changed hands, with trading activity in keeping with yesterday's. When a stock price moves up or down, watching the volume is a good way of identifying how significant that shift is. Investment valuation ratios can be very useful in determining the value of a stock, but it is very important to keep in mind that while some financial ratios have general rules (or a broad application), in most instances it is a prudent practice to look at a company's historical performance and use peer company/industry comparisons to put any given company's ratio in perspective. 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. DK has a PEG ratio of -0.26. While P/E ratios are important indicators of market value, a high P/E in and of itself is not bad because it may indicate a company whose earnings are growing very rapidly, so many investors look at the PEG ratio in order to get an idea of whether or not a particular P/E ratio is justified by underlying earnings growth.

Permian Basin (NYSE:PBT) is trading at $17.43 per share, down 2.6%. The company is currently trading a volume of 156,790 shares. This is 0.9 times the average volume over the last three months. If a stock price makes a big move up or down, volume lets us know the significance of that move. Investment valuation ratios can be very useful in estimating whether a stock price is too high, reasonable or a bargain investment opportunity. The price/book value ratio provides a way of evaluating whether a stock is relatively cheap or expensive. PBT has a P/B ratio of 871.5 which shows that its share price is higher than its book value. This implies that investors expect management to create more value from a given set of assets and/or that the market value of the firm's assets is significantly higher than their accounting value. All else being equal, a stock with a low P/B value ratio is more attractive than a stock with a high ratio. SEE: How Buybacks Warps The Price-To-Book Ratio

After rising 2.4%, Sandridge Mississippian Trust (NYSE:SDT) is currently trading at a share price of $25.36. The company's volume is currently 66,819 shares for the day, 0.3 times the average daily volume. If a stock price moves on high volume, this means that the change is a significant one. Understanding investment valuation ratios allows an investor to assess the true value of an individual stock. Dividend yield is a way to measure how much cash flow you are getting for each dollar invested in an equity position - in other words, how much "bang for your buck" you are getting from dividends. Dividend yield for SDT is a high 11.8%. This could mean either that the stock is underpriced or that the company has fallen on hard times and future dividends will not be as high as previous ones. A stock's dividend yield depends on the nature of a company's business, its posture in the marketplace (value or growth oriented), its earnings and cash flow, and its dividend policy. SEE: Investment Valuation Ratios: Dividend Yield

Oasis Petroleum (NYSE:OAS) is currently trading at $29.51 per share, a 2.2% increase. So far today, 938,507 shares have changed hands. 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. In making a decision about a potential or existing investment, valuation ratios are useful as a basis for seeing whether the stock price is too high, reasonable, or a bargain. The debt-equity (D/E) ratio compares the total liabilities for a company to its total shareholder equity. OAS has a D/E ratio of 110%, which is relatively high. This shows that the company's assets are financed primarily through debt. This easy-to-calculate ratio provides a general indication of a company's equity-liability relationship and is helpful to investors looking for a quick take on a company's leverage.

After an increase of 2.1%, Cabot Oil & Gas (NYSE:COG) has reached a current price of $41.48. The company's volume is currently 431,319 shares for the day, while it was 2.4 million shares yesterday. Volume indicates the level of interest that investors have in a company at its current price. Investors can use valuation ratios as tools to estimate what kind of deal a particular investment is. The debt ratio gives users a quick measure of the amount of debt that the company has on its balance sheets compared to its assets. COG has a debt ratio of 51.7%. However, one thing to note with this ratio: it isn't a pure measure of a company's debt (or indebtedness), as it also includes operational liabilities, such as accounts payable and taxes payable.

The Bottom Line No matter the economic climate, Wall Street will always have stocks that make major moves each week. It is important to weigh current activity against historical performance when making any investment decisions. Tools like valuation ratios and profit margins, however, are only as useful as the context you put them in; remember to take historical data and competitor performance into account.