DELAFIELD, Wis. (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.

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.

Impax Laboratories

Impax Laboratories (IPXL) , a specialty pharmaceutical company, develops, manufactures and markets bioequivalent pharmaceutical products and develops and markets branded products. This stock closed up 2.2% to $27.24 in Friday's trading session.

Friday's Volume: 1.45 million
Three-Month Average Volume: 697,377
Volume % Change: 130%

From a technical perspective, IPXL jumped notably higher here right above its 200-day moving average of $25.80 with above-average volume. This relative strength on Friday versus the overall market weakness is now starting to push shares of IPXL within range of triggering a near-term breakout trade. That trade will hit if IPXL manages to take out some near-term overhead resistance at $27.85 with high volume.

Traders should now look for long-biased trades in IPXL as long as it's trending above $25.60 and then once it sustains a move or close above $27.85 with volume that hits near or above 697,377 shares. If that breakout begins soon, then IPXL will set up to re-test or possibly take out its next major overhead resistance levels at $29.25 to its 52-week high at $31.04.

MicroStrategy

MicroStrategy(MSTR) - Get Report provides enterprise software platforms worldwide. This stock closed up 8.8% to $147.56 in Friday's trading session.

Friday's Volume: 232,000
Three-Month Average Volume: 62,652
Volume % Change: 250%

From a technical perspective, MSTR ripped sharply higher here right above its 200-day moving average of $130.74 and back above its 50-day moving average of $137.85 with above-average volume. This sharp spike higher on Friday also pushed shares of MSTR into breakout territory, since the stock took out some near-term overhead resistance levels at $143.45 to $146.61. Market players should now look for a continuation move to the upside in the short-term if MSTR manages to clear Friday's intraday high of $148.22 with high volume.

Traders should now look for long-biased trades in MSTR as long as it's trending above $143 or above $140 and then once it sustains a move or close above $148.22 with volume that hits near or above 62.652 shares. If that move gets underway soon, then MSTR will set up to re-test or possibly take out its next major overhead resistance level at its 52-week high of $155.86.

Anacor Pharmaceuticals

Anacor Pharmaceuticals (ANAC) , a biopharmaceutical company, focuses on discovering, developing and commercializing novel small-molecule therapeutics derived from its boron chemistry platform. This stock closed up 2% at $23.50 in Friday's trading session.

Friday's Volume: 973,000
Three-Month Average Volume: 567,108
Volume % Change: 65%

From a technical perspective, ANAC trended modestly higher here right off its 50-day moving average of $22.28 with above-average volume. This relative strength on Friday versus the overall market weakness is now starting to push shares of ANAC within range of triggering a major breakout trade. That trade will hit if ANAC manages to take out some key near-term overhead resistance levels at $24.04 to its 52-week high at $25.78 with high volume.

Traders should now look for long-biased trades in ANAC as long as it's trending above its 50-day at $22.89 or above more key near-term support at $21.50 and then once it sustains a move or close above those breakout levels with volume that's near or above 567,108 shares. If that breakout develops soon, the ANAC will set up to enter new 52-week-high territory above $25.78, which is bullish technical price action. Some possible upside targets off that breakout are $30 to $35.

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

-- Written by Roberto Pedone in Delafield, Wis.

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At the time of publication, author had no positions in stocks mentioned. Roberto Pedone, based out of Delafield, Wis., 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.