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.Major moves in volume can signal unusual activity, such as insider buying or selling -- or buying or selling by "superinvestors." >>5 Stocks Under $10 Poised to Pop 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. >>5 Big Stocks to Trade for Gains Ocean Rig UDW Ocean Rig UDW ( ORIG) is a Marshall Islands-registered international offshore drilling contractor. The firm provides oilfield services for offshore oil and gas exploration, development and production drilling. This stock is trading up 4.6% at $16.32 in recent trading. Today's Volume: 760,000 Average Volume: 129,752 Volume % Change: 916% From a technical perspective, ORIG is ripping higher here right off its 200-day moving average of $15.75 with monster upside volume. This move is quickly pushing shares of ORIG within range of triggering a major breakout trade. That trade will hit if ORIG manages to take out some near-term overhead resistance levels at $16.44 to $16.67 with high volume. Traders should now look for long-biased trades in ORIG as long as it's trending above its 50-day at $15.36 and then once it sustains a move or close above those breakout levels with volume that hits near or above 129,752 shares. If that breakout triggers soon, then ORIG will set up to re-test or possibly take out its next major overhead resistance level at $18.43. Cyberonics Cyberonics ( CYBX) is a medical device company engaged in the design, development, sales and marketing of implantable medical devices that provide a unique therapy for the treatment of refractory epilepsy and treatment-resistant depression. This stock is trading up 0.34% at $44.13 in recent trading.