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.>>5 Stocks With Big Insider Buying 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. >>5 Toxic Stocks You Should Sell With that in mind, let's take a look at several stocks rising on unusual volume recently. Receptos Receptos ( RCPT) is a biopharmaceutical company engaged in discovering, developing and commercializing therapeutics for immune disorders. Its product candidates span three distinct specialty disease areas. This stock closed up 5.4% to $23.85 in Wednesday's trading session. Wednesday's Volume: 281,000
Three-Month Average Volume: 63,652
Volume % Change: 359% >>5 Bargain Bin Stocks to Buy This Fall From a technical perspective, RCPT ripped higher here right above some near-term support at $21.67 with heavy upside volume. This move is quickly pushing shares of RCPT within range of triggering a major breakout trade. That trade will hit if RCPT manages to take out some near-term overhead resistance at $24 to its all-time high at $25 with high volume. Traders should now look for long-biased trades in RCPT as long as it's trending above some near-term support at $21 and then once it sustains a move or close above those breakout levels with volume that hits near or above 63,652 shares. If that breakout hits soon, then RCPT will set up to enter new all-time high territory, which is bullish technical price action. Some possible upside targets off that breakout are $30 to $35. Mazor Robotics Mazor Robotics ( MZOR) develops and markets surgical robots and complementing products for patients, surgeons and OR staff. The company's products are SpineAssist, DiscAssist and the C-InSight. This stock closed up 4.9% to $16.80 in Wednesday's trading session.