The Semiconductors sector (XLK) has climbed 0.2% so far today and here are its biggest movers:

Company | Market Cap | Percentage Change |

Mellanox (Nasdaq:MLNX) | $4.99 billion | -6.8% |

InvenSense (NYSE:INVN) | $999 million | +5.7% |

AIXTRON SE (Nasdaq:AIXG) | $1.43 billion | +4.8% |

Nvidia (Nasdaq:NVDA) | $8.51 billion | -4.4% |

M\x2FA-COM Technology Solutions (Nasdaq:MTSI) | $524.6 million | +3.9% |

Ultratech (Nasdaq:UTEK) | $898.4 million | -3.9% |

ASML Holding N.V (Nasdaq:ASML) | $23.62 billion | -3.3% |

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

**Mellanox**(Nasdaq:MLNX) is currently trading at a share price of $111.72, a 6.8% decline. This morning, the company is trading a volume of 1.2 million shares. 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/book value ratio is especially important for value investors as it can provide an indication of the true value of a company's assets at a time when its business model may be failing. MLNX's P/B ratio of 8.96 shows that its share price is higher than its book value. This may be a sign that the company is overvalued. P/B has its shortcomings but is still widely used as a valuation metric, more relevant for use by investors looking at capital-intensive or finance-related businesses, such as banks; book value does not carry much meaning for service-based firms with few tangible assets. SEE: Investment Valuation Ratios: Price/Book Value Ratio

**InvenSense**(NYSE:INVN) is at $12.92 per share after an increase of 5.7%. So far today, the company's volume is 573,182 shares, consistent with its current three-month average. 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 price/sales ratio is used for spotting recovery situations or for double-checking that a company's growth has not become overvalued. INVN's P/S ratio of 5.89 is on the high side. This could be a good sign if the share price increases. All things being equal, a low P/S ratio is good news for investors, while a very high one can be a warning sign.

Rising 4.8%,

**AIXTRON SE**(Nasdaq:AIXG) is currently trading at $14.91 per share. So far this morning, 34,285 shares have changed hands. This is consistent with its current daily average. If a stock price moves on high volume, this means that the change is a significant one. 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 debt ratio measures the leverage of a company, and a company's leverage is a good way to assess risk. The debt ratio for AIXG is a low 16.4%. In other words, the company is less sensitive to changes in business or interest rates since less of its cash flow is dedicated to paying off loan expenses. 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.

**Nvidia**(Nasdaq:NVDA) has fallen 4.4% and is currently trading at $13.12 per share. The company's volume is currently 9.4 million shares for the day, consistent with the volume from yesterday. The trading volume for a stock indicates the level of investor interest. 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. A company's price/earnings ratio (P/E ratio) provides a measure of how expensive or cheap a stock is. NVDA's P/E ratio is 18.1. A high P/E ratio indicates a stock that is expensive, while a low P/E ratio indicates a stock that is cheap. SEE: The P/E Ratio: A Good Market-Timing Indicator

After rising 3.9%,

**M\x2FA-COM Technology Solutions**(Nasdaq:MTSI) is currently trading at a share price of $12.02. So far today, the company's volume is 24,664 shares. Volume indicates the level of interest that investors have in a company at its current price. When estimating the value of a particular investment, valuation ratios provide a good basis for assessing the value of an individual stock. The price/book value ratio is calculated by dividing the current stock price by the company's book value per share. The P/B ratio for MTSI is 3.02, indicating that the stock is trading for more than its book value. 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. 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: Using The Price-To-Book Ratio To Evaluate Companies

At $32.68,

**Ultratech**(Nasdaq:UTEK) has slipped 3.9%. With 172,238 shares changing hands so far today, the company's volume is 1.2 times the 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 wide array of ratios can be used by investors to estimate the attractiveness of a potential or existing investment and get an idea of its valuation. While measuring a price/earnings ratio (P/E ratio) is a popular valuation technique, the measure cannot be calculated for companies without earnings, so some investors analyze the price/sales ratio. The P/S ratio for UTEK is 3.75, which is relatively high. In young companies, a high P/S ratio is a sign of sales growth that is expected to turn into earnings and cash flow. 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.

**ASML Holding N.V**(Nasdaq:ASML) is trading at $55.96 per share, down 3.3%. The company's volume for the day so far is 2.4 million shares. This is 1.7 times its average daily volume. 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. The easy-to-calculate debt ratio is helpful to investors looking for a quick take on the leverage for a company. ASML has a debt ratio of 48%, which is fairly low. This indicates that the company engages in conservative financing with opportunities to borrow in the future at no significant risk. As with all financial ratios, a company's debt ratio should be compared with the industry average or similar companies.

**The Bottom Line**On any given day, a particular stock may see positive or negative change in its share price. 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.