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 Poised for Breakouts 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 Stocks Under $10 Set to Soar Higher Philippine Long Distance Telephone Philippine Long Distance Telephone ( PHI) provides telecommunication services, including wireless services, fixed-line services and business process outsourcing services. This stock is trading up 1% at $70.17 in recent trading. Today's Volume: 241,000 Average Volume: 138,058 Volume % Change: 225% >>5 Must-See Charts to Trade in April From a technical perspective, PHI is bouncing modestly higher here right above its 50-day moving average of $69.27 with above-average volume. This move is quickly pushing shares of PHI within range of triggering a near-term breakout trade. That trade will hit if PHI manages to take out some near-term overhead resistance levels at $71 to its double-top zone at $71.98 with high volume. Traders should now look for long-biased trades in PHI as long as it's trending above its 50-day at $69.27, and then once it sustains a move or close above those breakout levels with volume that hits near or above 138,058 shares. If that breakout hits soon, then PHI will set up to re-test or possibly take out its 52-week high at $74.08. Workday Workday ( WDAY) is a provider of enterprise cloud-based applications for human capital management, payroll, financial management, time tracking, procurement and employee expense management. This stock is trading up 1.4% at $60.94 in recent trading.