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. >>4 Big Stocks to Buy in February -- and One to Sell Liquidity Service Liquidity Service ( LQDT), an online auction marketplace for surplus and salvage assets, is trading up 3.4% at $32.98 in recent trading. Today's Volume: 1.48 million Average Volume: 666,737 Volume % Change: 233% From a technical perspective, LQDT is spiking higher here right above its recent low of $29.30 with above-average volume. This stock gapped down sharply on Thursday from around $41 to that low of $29.30 with heavy downside volume. That said, the stock is starting to bounce higher here and move within range of triggering a near-term breakout trade. That trade will hit if LQDT mangos to take out its gap down day high of $34.08 with high volume. Traders should now look for long-biased trades in LQDT as long as it's trending above Thursday's close of $31.87, and then once it sustains a move or close above $34.08 with volume that hits near or above 666,737 shares. If that breakout triggers soon, then LQDT will set up to re-fill some of that gap that started near $41. Look for a fast move into that gap if LQDT gets volume on a move above $34.08 in the near future.