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.

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

Stocks with unusual volume are something that I tweet about on a daily basis. These are also the exact type of stocks that I love to trade and alert to my subscribers in real-time.

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 recently.

Reata Pharmaceuticals

  • Wednesday's Volume: 304,000
  • Three-Month Average Volume: 111,928
  • Volume % Change: 238%

Reata Pharmaceuticals  (RETA - Get Report)  focuses on identifying, developing and commercializing product candidates that modulate the activity of key regulatory proteins involved in the biology of mitochondrial function, oxidative stress and inflammation to address the unmet medical needs of patients with various serious or life-threatening diseases. This stock closed up 4.7% to $27.71 in Wednesday's trading session.

From a technical perspective, Reata Pharmaceuticals jumped sharply higher on Wednesday right above some near-term support at $26 a share with strong upside volume flows. This high-volume rip to the upside is now quickly pushing shares of Reata Pharmaceuticals within range of triggering a major breakout trade above some key overhead resistance levels. That trade will trigger if this stock manages to take out some near-term overhead resistance levels at $29.65 to $30.50 a share and then above its all-time high of $32.22 a share with high volume.

Traders should now look for long-biased trades in Reata Pharmaceuticals as long as it's trending above some near-term support levels at $26 or $25 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 111,928 shares. If that breakout fires off soon, then this stock will set up to enter new all-time-high territory above $32.22, which is bullish technical price action. Some possible upside targets off that move are $35 to $40 a share.

Diplomat Pharmacy

  • Wednesday's Volume: 1.34 million
  • Three-Month Average Volume: 511,022
  • Volume % Change: 203%

Diplomat Pharmacy  (DPLO - Get Report) operates as an independent specialty pharmacy in the U.S. This stock closed up 2.5% to $29.05 in Wednesday's trading session.

From a technical perspective, Diplomat Pharmacy spiked notably higher on Wednesday off some previous support from April at around $27.54 a share with strong upside volume flows. This stock has been downtrending badly over the last two months, with shares sliding lower off its all-time high of $38.94 a share to its recent low of $27.61 a share. During that downtrend, shares of Diplomat Pharmacy have been making mostly lower highs and lower lows, which is bearish technical price action. That said, this stock has now started to rebound higher off some previous support at $27.54 a share, and it's quickly trending within range of triggering a near-term breakout trade. That trade will trigger if this stock manages to take out Wednesday's intraday high of $29.05 a share to some more near-term resistance at $29.50 a share with high volume.

Traders should now look for long-biased trades in Diplomat Pharmacy as long as it's trending above some past support at $27.54 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 511,022 shares. If that breakout fires off soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at its 20-day moving average of $31.43 a share to its 200-day moving average of $31.73 a share, or even $33 to its 50-day moving average of $33.91 a share.

Collegium Pharmaceuticals

  • Wednesday's Volume: 635,000
  • Three-Month Average Volume: 181,281
  • Volume % Change: 303%

Collegium Pharmaceuticals  (COLL - Get Report)  develops and commercializes abuse-deterrent products that incorporate its DETERx platform technology for the treatment of chronic pain and other diseases. This stock closed up 8.4% to $12.82 in Wednesday's trading session.

From a technical perspective, Collegium Pharmaceuticals ripped sharply higher on Wednesday right above some previous resistance at $11.73 a share with strong upside volume flows. This stock has been uptrending strong over the last few weeks, with shares moving higher off its low of $8.24 a share to its intraday high on Wednesday of $12.98 a share. During that uptrend, shares of Collegium Pharmaceuticals have been making mostly higher lows and higher highs, which is bullish technical price action. This high-volume rip to the upside is now quickly pushing this stock within range of triggering a near-term breakout trade. That trade will trigger if this stock manages to take out some near-term overhead resistance levels at $13 to $13.03 a share and then above $13.50 to $14.08 a share with high volume.

Traders should now look for long-biased trades in Collegium Pharmaceuticals as long as it's trending above Wednesday's intraday low of $11.86 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 181,281 shares. If that breakout hits soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $15 to $15.50, or even its 200-day moving average of $16.28 to $17.50 a share.

Life Storage

  • Wednesday's Volume: 682,000
  • Three-Month Average Volume: 593,317
  • Volume % Change: 385%

Life Storage  (LSI - Get Report)  is a real estate investment trust. It invests in the real estate markets of the U.S. This stock closed up 1% to $91.33 in Wednesday's trading session.

From a technical perspective, Life Storage spiked notably higher on Wednesday right above some near-term support at $88.38 a share and back above its 20-day moving average of $90.29 a share with above-average volume. This high-volume bump to the upside is now quickly pushing shares of Life Storage within range of triggering a big breakout trade above some key overhead resistance levels. That trade will trigger if this stock manages to take out some near-term overhead resistance levels at $92 to $94.36 a share and then above $94.96 a share to its 50-day moving average of $95.10 a share with high volume.

Traders should now look for long-biased trades in Life Storage as long as it's trending above some key near-term support at $88.38 a share or above its 52-week low of $86.45 a share and then once it sustains a move or close above those breakout levels with volume that registers near or above 593,317 shares. If that breakout triggers soon, then this stock will set up to re-fill some of its previous gap-down-day zone from August that started near $102 a share.

Radcom

  • Wednesday's Volume: 470,000
  • Three-Month Average Volume: 172,283
  • Volume % Change: 209%

Radcom  (RDCM - Get Report)  provides service assurance and customer experience monitoring solutions for communication service providers. This stock closed up 5.4% to $20.22 in Wednesday's trading session.

From a technical perspective, Radcom ripped sharply higher on Wednesday right above its 20-day moving average of $18.88 a share with strong upside volume flows. This high-volume rip to the upside managed to push shares of Radcom into breakout and new 52-week high territory, after the stock closed above some near-term overhead resistance at $19.30 a share. Market players should now look for a continuation move to the upside in the short-term if this stock manages to close above Wednesday's intraday high of $20.23 a share with strong volume.

Traders should now look for long-biased trades in Radcom as long as it's trending above $19.30 or above its 20-day moving average of $18.88 a share and then once it sustains a move or close above $20.23 a share with volume that hits near or above 172,283 shares. If that move gets underway soon, then this stock will set up to enter new 52-week-high territory, which is bullish technical price action. Some possible upside targets off that move are $25 to $30 a share.

Harley-Davidson

  • Wednesday's Volume: 9.44 million
  • Three-Month Average Volume: 2.99 million
  • Volume % Change: 253%

Harley-Davidson  (HOG - Get Report)  primarily manufactures cruiser and touring motorcycles. This stock closed up 3.9% to $52.42 in Wednesday's trading session.

From a technical perspective, Harley-Davidson spiked notably higher on Wednesday back above both its 50-day moving average of $51.68 a share and its 20-day moving average of $51.94 a share with strong upside volume flows. This high-volume bump to the upside is now quickly pushing shares of Harley-Davidson within range of triggering a near-term breakout trade. That trade will trigger if this stock manages to take out Wednesday's intraday high of $54.12 to $54.28 a share and then above more near-term resistance at $55 a share with high volume.

Traders should now look for long-biased trades in Harley-Davidson as long as it's trending above some near-term support levels at $50 a share or at $49.11 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 2.99 million shares. If that breakout fires off soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $56.95 to its 52-week high of $57.33 a share, or even $60 a share.

Nexstar Broadcasting

  • Wednesday's Volume: 1.27 million
  • Three-Month Average Volume: 469,541
  • Volume % Change: 178%

Nexstar Broadcasting  (NXST - Get Report)  operates as a television broadcasting and digital media company in the U.S. This stock closed up 1% to $52.55 in Wednesday's trading session.

From a technical perspective, Nexstar Broadcasting trended modestly higher on Wednesday right above some near-term support levels at $50.06 a share and its 200-day moving average of $49.49 a share with strong upside volume flows. This high-volume bump to the upside is now quickly pushing shares of Nexstar Broadcasting within range of triggering a near-term breakout trade above some key overhead resistance levels. That trade will trigger if this stock manages to take out both its 50-day moving average of $52.79 a share and its 20-day moving average of $53.11 a share with high volume.

Traders should now look for long-biased trades in Nexstar Broadcasting as long as it's trending above some key near-term support levels at $50.06 a share or above its 200-day moving average of $49.49 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 469,541 shares. If that breakout triggers soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $55 to $55.73, or even $59.40 to $60.80 a share.

Marriott International

  • Wednesday's Volume: 15.92 million
  • Three-Month Average Volume: 3.19 million
  • Volume % Change: 477%

Marriott International  (MAR - Get Report)  operates, franchises and licenses hotels and timeshare properties worldwide. This stock closed up 0.29% to $70.14 in Wednesday's trading session.

From a technical perspective, Marriott International trended modestly higher on Wednesday back above its 20-day moving average of $70.06 a share with monster upside volume flows. This stock has been uptrending over the last few weeks, with shares moving higher off its low of $66.25 a share to its recent high of $70.69 a share. During that uptrend, this stock has been consistently making higher lows and higher highs, which is bullish technical price action. That move has now started to push shares of Marriott International within range of triggering a near-term breakout trade. That trade will trigger if this stock manages to take out some near-term overhead resistance levels at $70.69 to its 50-day moving average of $70.82 a share with high volume.

Traders should now look for long-biased trades in Marriott International as long as it's trending above some near-term support levels at $68.50 or at $68 a share and then once it sustains a move or close above those breakout levels with volume that hits near or above 3.19 million shares. If that breakout hits soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $73 to $73.67, or even $77.60 to its 52-week high of $79.88 a share.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.