MADISON, 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." >>5 Stocks Poised to Pop on Bullish Earnings 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 Rocket Stocks to Buy as Stocks Bounce Matrix Service Matrix Service ( MTRX) provides construction and repair and maintenance services mainly to the energy and energy related industries. This stock closed up 7% at $17.40 on Tuesday. Tuesday's Volume: 654,000
Average Volume: 151,838
Volume % Change: 318% >>5 Stocks Poised for Breakouts From a technical perspective, MTRX ripped higher here right above some near-term support at $16.10 with heavy upside volume. This move is quickly pushing shares of MTRX within range of triggering a near-term breakout trade. That trade will hit if MTRX manages to take out its 52-week high at $17.93 with high volume. Traders should now look for long-biased trades in MTRX as long as it's trending above Tuesday's low of $16.58 or above that key support area at $16.10 and then once it sustains a move or close above $17.93 with volume that hits near or above 151,838 shares. If that breakout triggers soon, then MTRX will set up to enter new 52-week-high territory, which is bullish technical price action. Some possible upside targets off that breakout are $20 to $23. ViroPharma ViroPharma ( VPHM) is dedicated to the development and commercialization of products that address serious diseases, with a focus on products used by physician specialists or in hospital settings. This stock closed up 2.3% at $27.68 on Tuesday.