Stock Quotes in this Article: MANT, NXPI, OPEN, IMPV

WINDERMERE, Fla. (Stockpickr) -- Professional traders running mutual funds and hedge funds don't just look at a stock's price moves; they also track big changes in volume activity. Often when above-average volume moves into an equity, it precedes a large spike in volatility.

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Major moves in volume can signal unusual activity, such as insider buying or selling -- or buying or selling by "superinvestors."

Unusual volume can also be a major signal that hedge funds and momentum traders are piling into a stock ahead of a catalyst. These types of traders like to get in well before a large spike, so it's always a smart move to monitor unusual volume. That said, remember to combine trend and price action with unusual volume. Put them all together to help you decipher the next big trend for any stock.

With that in mind, let's take a look at several stocks rising on unusual volume today.

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ManTech International (MANT)

This company is a provider of innovative technologies and solutions for mission-critical national security programs. This stock is trading up 2.9% at $25.33 in recent trading.

Today's Volume: 646,000

Average Volume: 145,982

Volume % Change: 546%

From a technical perspective, MANT is trending higher here right off some near-term support at $24.50 with above-average volume. This move is quickly pushing MANT within range of triggering a near-term breakout trade. That trade will hit if MANT manages to take out its 50-day moving average at $25.72 with high volume.

Traders should now look for long-biased trades in MANT as long as it's trending above $24.50 or $24.11, and then once it sustains a move or close above $25.72 with volume that hits near or above 145,982 shares. If that breakout triggers, then MANT will set up to re-test or possibly take out its next major overhead resistance levels at $26.50 to $27.54. Any high-volume move above $27.54 will then give MANT a chance to re-fill some of its previous gap down zone from last May that started near $31.

Imperva (IMPV)

This company engages in development & sale of data security solutions that provide visibility and control over high value business data across critical systems within the data center. This stock is trading up 6.6% at $36.51 in recent trading.

Today's Volume: 376,000

Average Volume: 190,927

Volume % Change: 200%

From a technical perspective, IMPV is soaring here right above some near-term support at $34 to $33.50 with above-average volume. This move has started to push IMPV into breakout territory, since the stock has flirted with some near-term overhead resistance levels at $36.90 to $37.71. At last check, IMPV has hit an intraday high of $37.97 and volume is well above its three-month average action of 190,927 shares.

Traders should now look for long-biased trades in IMPV as long as it's trending above $36.90 to $37.71 with strong upside volume flows. I would consider any upside volume day that registers near or above 190,927 shares as bullish. If IMPV can maintain that trend, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $38.93 to $42.41. Any high-volume move above $42.41 will then push IMPV into new all-time high territory, which is bullish technical price action.

OpenTable (OPEN)

This company provides solutions that form an online network connecting reservation-taking restaurants & people who dine at those restaurants. Its solutions are Electronic Reservation Book, for restaurant customers and reservation website for diners. This stock is trading up 2.9% at $50.75 in recent trading.

Today's Volume: 991,000

Average Volume: 437,721

Volume % Change: 202%

Shares of OPEN are trending higher today after the company reported quarterly results that beat analysts' estimates, helped by an increase in the number of seated diners, and the company expects mobile devices to drive more revenue.

From a technical perspective, OPEN are moving modestly higher here right above some near-term support at $48.81 and back above its 50-day moving average at $50.10 with above-average volume. This move is quickly pushing shares of OPEN within range of triggering a near-term breakout trade. That trade will hit if OPEN manages to take out some near-term overhead resistance at $52 with high volume.

Traders should now look for long-biased trades in OPEN as long as it's trending above its 50-day at $50.10, and then once it sustains a move or close above $52 with volume that hits near or above 437,721 shares. If that breakout hits soon, then OPEN will set up to re-test or possibly take out its next major overhead resistance levels at $54 to $55.95. Any high-volume move above $55.95 will then push shares of OPEN into new 52-week high territory, which is bullish technical price action.

NXP Semiconductor (NXPI)

This company provides high performance mixed signal and standard product solutions. Its solutions are used for automotive, identification, wireless infrastructure, lighting, consumer and computing applications. This stock is trading up 4.7% at $31.92 in recent trading.

Today's Volume: 3.78 million

Average Volume: 1.63 million

Volume % Change: 207%

From a technical perspective, NXPI is ripping higher here right above some near-term support at $30 with above-average volume. This move has started to push shares of NXPI into breakout territory, since the stock has cleared some near-term overhead resistance at $31.28.

Traders should now look for long-biased trades in NXPI as long as it's trending above $31.28 with strong upside volume flows. I would consider any upside volume day that registers near or above 1.63 million shares as bullish. If NXPI can maintain that trend, then this stock will set up to re-test or possibly take out its next major overhead resistance level at $35.32.

To see more stocks rising on unusual volume, check out the Stocks Rising On Unusual Volume portfolio on Stockpickr.

-- Written by Roberto Pedone in Winderemere, Fla.

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At the time of publication, author had no positions in stocks mentioned.

Roberto Pedone, based out of Windermere, Fla., is an independent trader who focuses on technical analysis for small- and large-cap stocks, options, futures, commodities and currencies. Roberto studied international business at the Milwaukee School of Engineering, and he spent a year overseas studying business in Lubeck, Germany. His work has appeared on financial outlets including CNBC.com and Forbes.com. You can follow Pedone on Twitter at www.twitter.com/zerosum24 or @zerosum24.