Stock Quotes in this Article: CATM, EXLP, GEOY, HCSG, LGND, MEOH, PDFS

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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PDF Solutions (PDFS)

This company provides infrastructure technologies and services to improve yield and optimize performance of integrated circuits. This stock is trading up 5.4% at $15.21 in recent trading.

Today's Volume: 213,000

Average Volume: 117,854

Volume % Change: 217%

From a technical perspective, PDFS is ripping higher here right off its 50-day moving average of $14.08 with above-average volume. This move is starting to push shares of PDFS into breakout territory, since the stock has cleared some near-term overhead resistance levels at $14.79 to $14.95. Shares of PDFS are now trading in new 52-week high territory, which is bullish technical price action.

Traders should now look for long-biased trades in PDFS as long as it's trending above its 50-day at $14.08, and then once it sustains a move or close above those breakout levels with volume that hits near or above 117,854 shares. If PDFS can maintain this trend, then this stock has a great chance of tagging $18 to $20 in the near future.

GeoEye (GEOY)

This company is a provider of imagery, imagery information products and image processing services. This stock is trading up 7.2% at $36.46 in recent trading.

Today's Volume: 524,000

Average Volume: 174,511

Volume % Change: 439%

From a technical perspective, GEOY is ripping higher here right above its 50-day moving average of $30.99 with above-average volume. This move has solidly pushed shares of GEOY into breakout territory, since the stock has cleared some near-term overhead resistance that sits just above $34. This move has also pushed GEOY into new 52-week high territory, which is bullish technical price action.

Traders should now look for long-biased trades in GEOY as long as it's trending above some past overhead resistance at $37.07 with strong upside volume flows. I would consider any upside volume day that registers near or above its three-month average action of 174,511 shares as bullish. If GEOY can maintain that trend, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $39.25 to $42.31.

Ligand Pharmaceuticals (LGND)

This company is focused on drug discovery & early-stage development of pharmaceuticals that address critical unmet medical needs or that are more effective or safer than existing therapies, more convenient to administer & are cost effective. This stock is trading up 5.7% at $20.60 in recent trading.

Today's Volume: 234,000

Average Volume: 143,311

Volume % Change: 146%

Shares of LGND are ripping higher today after the company said it has received a milestone payment of 620,000 shares of common stock in newly public partner Retrophin (RTRX).

From a technical perspective, LGND is bouncing higher here right above some near-term support at $19.03 with above-average volume. This stock has been uptrending strongly for the last two months, with shares moving higher from its low of $14.75 to its recent high of $21.75. During that move, shares of LGND have been mostly making higher lows and higher highs, which is bullish technical price action. That move is quickly pushing LGND within range of triggering a major breakout trade. That trade will hit if LGND takes out some near-term overhead resistance levels at $21.50 to $21.75 with high volume.

Traders should now look for long-biased trades in LGND as long as it's trending above some key near-term support at $19.03, and then once it sustains a move or close above those breakout levels with volume that hits near or above 143,311 shares. If that breakout triggers soon, then LGND will set up to re-test or possibly take out its next major overhead resistance levels at $22 to $23. Any move above those levels could then put $25 into focus for shares of LGND.

 

Exterran Partners (EXLP)

This company is engaged in the natural gas compression and a provider of services and equipment for oil & gas production, processing, treating, transportation and storage. This stock is trading up 2.6% at $22.60 in recent trading.

Today's Volume: 191,000

Average Volume: 115,926

Volume % Change: 179%

Shares of EXLP are moving higher today after Credit Suisse upgraded the stock to outperform from neutral.

From a technical perspective, EXLP is trending higher here right above some near-term support at $21.75 with above-average volume. This move is quickly pushing EXLP within range of triggering a near-term breakout trade. That trade will hit if EXLP manages to take out some near-term overhead resistance levels at $22.96 to $23.06 and then some past overhead resistance at $23.35 with high volume.

Traders should now look for long-biased trades in EXLP as long as it's trending above its 50-day at $21.45, and then once it sustains a move or close above those breakout levels with volume that hits near or above 115,926 million shares. If that breakout hits soon, then EXLP will set up to re-test or possibly take out its next major overhead resistance levels at $24 to $24.88. Any move above those levels will then put $26.97 into focus for shares of EXLP.

Healthcare Services Group (HCSG)

This company provides housekeeping, laundry, linen, facility maintenance and dietary services to the health care industry, including nursing homes, retirement complexes, rehabilitation centers and hospitals located throughout the U.S. This stock is trading up 2.5% at $24 in recent trading.

Today's Volume: 491,000

Average Volume: 349,064

Volume % Change: 148%

Shares of HCSG are moving higher today after Benchmark upgraded the stock from hold to buy.

From a technical perspective, HCSG is gapping higher here back above its 50-day moving average of $23.26 with above-average volume. This move is quickly pushing shares of HCSG within range of triggering a major breakout trade. That trade will hit if HCSG manages to clear some near-term overhead resistance levels at $24 to $24.49 with high volume. At last check, HCSG has hit an intraday high of $24.08 and volume is well above its three-month average action of 349,064 shares.

Traders should now look for long-biased trades in HCSG as long as it's trending above its 50-day at $23.26, and then once it sustains a move or close above those breakout levels with volume that hits near or above 349,064 shares. If that breakout triggers soon, then HCSG will set up to enter new 52-week high territory, which is bullish technical price action. Some possible upside targets off that breakout are $28 to $30.

Cardtronics (CATM)

This company provides ATM management and equipment-related services to nationally-known retail merchants as well as smaller retailers and operators of facilities such as shopping malls and airports. This stock is trading up 2.4% at $24.75 in recent trading.

Today's Volume: 545,000

Average Volume: 282,772

Volume % Change: 196%

From a technical perspective, CATM is spiking higher here right off its 50-day moving average of $24.03 with above-average volume. This stock has been uptrending modestly for the last month, with shares moving higher from its low of $22.20 to its recent high of $24.78. During that move, shares of CATM have been consistently making higher lows and higher highs, which is bullish technical price action. That move has now pushed CATM within range of triggering a near-term breakout trade. That trade will hit if CATM clears some near-term overhead resistance at $24.78 to $25.50 with high volume.

Traders should now look for long-biased trades in CATM as long as it's trending above some key near-term support at $23.13, and then once it sustains a move or close above $24.78 to $25.50 with volume that this near or above 282,772 shares. If that breakout triggers soon, then CATM will set up to re-test or possibly take out its next major overhead resistance level at its 200-day moving average of $27.65.

Methanex (MEOH)

This company is the supplier of methanol to each of the major international markets of North America, Asia Pacific and Europe as well as Latin America. This stock is trading up 1.7% at $33.74 in recent trading.

Today's Volume: 347,000

Average Volume: 202,333

Volume % Change: 178%

From a technical perspective, MEOH is bouncing modestly higher here right above some near-term support at $33 with above-average volume. This stock has been uptrending strongly for the last three months, with shares soaring from its low of $26.40 to its recent high of $33.82. During that move, shares of MEOH have been consistently making higher lows and higher highs, which is bullish technical price action. That move has now pushed MEOH within range of triggering a near-term breakout trade. That trade will hit if MEOH takes out some near-term overhead resistance at $33.82 with high volume.

Traders should now look for long-biased trades in MEOH as long as it's trending above some key near-term support at $32.50, and then once it sustains a move or close above $33.82 with volume that hits near or above 202,333 shares. If that breakout triggers soon, then MEOH will set up to re-test or possibly take out its next major overhead resistance level at $34.88.

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.