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.>>5 Huge Trades for a Volatile 2013 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 today. MagicJack VocalTec ( CALL) This company provides telecommunication services. Its services include VoIP services such as magicJack, magicTalk and MagicJack Plus. It also provides Carrier Solutions like infrastructure solutions, Essetra Solutions and applications. This stock is trading up 8.9% at $17.74 in recent trading. Today's Volume: 1.04 million Average Volume: 347,441 Volume % Change: 382% From a technical perspective, CALL is gapping sharply higher here right above some near-term support at $15.50 with monster upside volume. This stock has been trending range bound for the last month, with shares moving between $15.50 on the downside and $17.95 on the upside. Shares of CALL have started to challenge its 50-day moving average at $18.07 today and the upper-end its recent range. At last check, CALL has hit an intraday high of $18.50 and volume is well above its three-month average action of 347,441 shares. Traders should now look for long-biased trades in CALL as long as it's trending above $17.67 to $18.07, and then once it sustains a breakout above $18.50 with volume that hits near or above 347,411 shares. If that breakout triggers soon, then CALL will set up to re-test or possibly take out its next major overhead resistance levels at $20.39 to its 200-day moving average at $20.78.