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."

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.

Trinity Biotech

  • Monday's Volume: 176,000
  • Three-Month Average Volume: 159,642
  • Volume % Change: 113%

Trinity Biotech  (TRIB - Get Report)  acquires, develops, manufactures and markets medical diagnostic products for the clinical laboratory and point-of-care segments of the diagnostic market. This stock is trading up 8.9% to $12.24 in Monday's trading session.

From a technical perspective, Trinity Biotech is ripping sharply higher here right above some near-term support at $11.10 a share with above-average volume. This stock has been attempting to carve out a major bottoming chart pattern over the last month and change, with shares finding some buying interest at $11, $10.83 and $11.10 a share.

This high-volume spike to the upside on Monday is now quickly pushing this stock 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 its 50-day moving average of $12.99 to some more near-term overhead resistance at $13.24 a share with high volume.

Traders should now look for long-biased trades in Trinity Biotech as long as it's trending above Monday's intraday low of $11.75 and then once it sustains a move or close above those breakout levels with volume that hits near or above 159,642 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 $14 to $15, or even $16 a share.

Fluidigm

  • Monday's Volume: 574,000
  • Three-Month Average Volume: 679,114
  • Volume % Change: 148%

Fluidigm  (FLDM - Get Report)  creates, manufactures and markets technologies and life science tools focused on the exploration and analysis of single cells, as well as the industrial application of genomics. This stock is trading up 5.9% to $11.45 in Monday's trading session.

From a technical perspective, Fluidigm is spiking higher here right above its 50-day moving average of $9.96 a share with decent upside volume flows. This jump to the upside on Monday is now starting to push shares of Fluidigm within range of triggering a major breakout trade above some key near-term overhead resistance levels. That trade will hit if this stock manages to take out some key near-term overhead resistance levels at $12.06 to $12.38 a share and then above $12.97 to $13.25 a share with high volume.

Traders should now look for long-biased trades in Fluidigm as long as it's trending above its 50-day moving average of $9.96 a share and then once it sustains a move or close above those breakout levels with volume that registers near or above 679,114 shares. If that breakout gets started soon, then this stock will set up to re-fill some of its previous gap-down-day zone from July that started near $20 a share.

Greenbrier

  • Monday's Volume: 552,00
  • Three-Month Average Volume: 605,009
  • Volume % Change: 114%

Greenbrier  (GBX - Get Report) , designs, manufactures and markets railroad freight car equipment in North America and Europe. This stock is trading up 5.9% to $40.37 in Monday's trading session.

From a technical perspective, Greenbrier is ripping sharply higher here right off its 50-day moving average of $36.99 with strong upside volume flows. This strong spike to the upside on Monday is now quickly pushing shares of Greenbrier within range of triggering a big breakout trade above some key near-term overhead resistance levels. That trade will trigger if this stock manages to take out some near-term overhead resistance levels at $40.44 to $42.50 a share with high volume.

Traders should now look for long-biased trades in Greenbrier as long as it's trending above its 50-day at $36.99 and then once it sustains a move or close above those breakout levels with volume that hits near or above 605,009 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 $46 to $47.75, or even $49 to its 200-day moving average of $50.29 a share.

Conn's

  • Monday's Volume: 955,000
  • Three-Month Average Volume: 837,220
  • Volume % Change: 142%

Conn's  (CONN - Get Report)  operates as a specialty retailer of durable consumer goods and related services in the U.S. This stock is trading up 12.4% to $21.33 in Monday's trading session.

From a technical perspective, Conn's is ripping sharply higher here right above its recent low of $18.90 with strong upside volume flows. This stock has been downtrending badly over the last four months, with shares falling sharply off its high of $43.95 to its recent low of $18.90 a share. During that downtrend, shares of Conns have been consistently making lower highs and lower lows, which is bearish technical price action. That said, this stock has now started to rip higher off that $18.90 low and it's now quickly moving 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 $22 to its 20-day moving average of $22.12 a share and then above more resistance at $22.50 a share with high volume.

Traders should now look for long-biased trades in Conn's as long as it's trending above Monday's intraday low of $19.43 and then once it sustains a move or close above those breakout levels with volume that registers near or above 837,220 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 $24.97 to its 50-day moving average of $25.15, or even $26.50 a share.

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