The Transportation sector (IYT) is currently ahead of the overall market, down only 1.5%, and its biggest movers are currently:

Company | Market Cap | Percentage Change |

RailAmerica, Inc. (NYSE:RA) | $1.25 billion | +9.8% |

Teekay LNG Partners L.P. (NYSE:TGP) | $2.57 billion | -3.8% |

Atlas Air Worldwide Holdings, Inc. (Nasdaq:AAWW) | $1.15 billion | -3.5% |

Grupo Aeroportuario del Pacifico (ADR) (NYSE:PAC) | $2.22 billion | -3.2% |

GulfMark Offshore, Inc. (NYSE:GLF) | $989.8 million | -3.1% |

AMERCO (Nasdaq:UHAL) | $1.82 billion | -2.5% |

Grupo Aeroportuario del Sureste (ADR) (NYSE:ASR) | $2.56 billion | -2.3% |

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**RailAmerica**(NYSE:RA) has risen 9.8% and is currently trading at $27.25 per share. The company's volume for the day so far is 3.9 million shares. When a stock price moves up or down, watching the volume is a good way of identifying how significant that shift is. A company's value as an investment is more easily estimated using valuation ratios such as 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. In a nutshell, the price/sales ratio shows how much Wall Street values every dollar of the company's sales. RA's P/S ratio of 1.9 is on the high side. In young companies, a high P/S ratio is a sign of sales growth that is expected to turn into earnings and cash flow. All things being equal, a low P/S ratio is good news for investors, while a very high one can be a warning sign.

At $38.15,

**Teekay LNG Partners**(NYSE:TGP) has slipped 3.8%. The company's volume is currently 75,048 shares for the day, on pace to finish the day below yesterday's volume of 199,169 shares. Price change alone is not enough to know how a stock is doing. Volume is an important secondary indicator used to confirm trends suggested by price movement. 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 ratio gives users a quick measure of the amount of debt that the company has on its balance sheets compared to its assets. TGP has a high debt ratio of 71%. This might mean that the company now has low borrowing capacity, which reduces it's financial flexibility. 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.

**Atlas Air Worldwide Holdings**(Nasdaq:AAWW) is currently trading at a share price of $42.02, a 3.5% decline. This morning, the company's volume is 35,403 shares. This is 0.2 times its average daily volume. Volume is used to evaluate how meaningful the price movement of a stock is. Valuation ratios allow the investor to make a quick determination as to a company's investment value. The debt-equity (D/E) ratio is a leverage ratio. AAWW has a D/E ratio of 67%. 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.

**Grupo Aeroportuario del Pacifico**(NYSE:PAC) has fallen 3.2%. At 14,515 shares, the company's volume so far today is consistent with its current three-month average. 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. A company's investment value can be estimated using valuation ratios such as 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 capitalization ratio is calculated by dividing long-term debt by the sum of long-term debt and shareholders' equity. PAC's capitalization ratio is 5.8%, which is relatively low. Investors generally consider a company with low debt and high equity levels is a good quality investment. This ratio is considered to be one of the more meaningful of the "debt" ratios - it delivers the key insight into the use of leverage by a company.

**GulfMark Offshore**(NYSE:GLF) has fallen 3.1% and is currently trading at $35.75 per share. This morning, the company is trading a volume of 48,733 shares. Volume is also used as a secondary indicator to help confirm what the price movement is suggesting. Investment valuation ratios provide investors with an estimation, albeit a simplistic one, of the value of a stock. The price/book value ratio provides a way of evaluating whether a stock is relatively cheap or expensive. GLF has a P/B ratio of 0.94, which shows that its book value is higher than its share price. This is due to one of two possibilities: that the stock is being unfairly or incorrectly undervalued by investors because of some transitory circumstance and represents an attractive buying opportunity at a bargain price or that the market's low opinion and valuation of the company are correct, at least over the foreseeable future. A weakness of the P/B value ratio is that while the price component is easily determined by looking at the stock quote, the book value component is more difficult to estimate and more open to individual interpretation and analysis. SEE: Investment Valuation Ratios: Price/Book Value Ratio

Slipping 2.5%,

**AMERCO**(Nasdaq:UHAL) is currently trading at $90.34 per share. At 4,216 shares, the company's volume so far today is lighter than yesterday's volume of 11,474 shares. In technical analysis, trading volume is used to determine the strength of a market indicator. Valuation ratios allow the investor to make a quick determination as to a company's investment value. One of the most important estimates of stock market valuation is the price/earnings ratio (P/E ratio). UHAL is in line with the industry average with a P/E ratio of 9.2. To determine the P/E ratio, an investor divides the market price of the stock by the earnings-per-share (EPS) of the stock. SEE: How To Use The P/E Ratio And PEG To Tell The Future Of A Stock

Falling 2.3%,

**Grupo Aeroportuario del Sureste**(NYSE:ASR) is currently at a share price of $83.31. The company's volume for the morning is 21,838 shares. This is 0.2 times the average daily volume. 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 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 price/sales ratio measures a company's stock market value by its total revenues or alternatively, a company's price per share by its revenue per share. The P/S ratio for ASR is 5.63, which is relatively high. This could be a good sign if the share price increases. It is important to compare P/S ratios for companies in the same industry, as ratios can vary quite widely for companies in different industries.

**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.