DELAFIELD, 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.>>5 Stocks Insiders Love Right Now 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. >>5 Toxic Stocks to Sell Before It's Too Late With that in mind, let's take a look at several stocks rising on unusual volume today. Aspen Technology Aspen Technology ( AZPN) supplies process optimization software, which allows manufacturers to implement best practices for optimizing their engineering, manufacturing and supply chains. This stock closed up 1.4% at $37.64 in Wednesday's trading session. Wednesday's Volume: 637,000
Three-Month Average Volume: 410,726
Volume % Change: 59% >>5 Stocks Set to Soar on Bullish Earnings From a technical perspective, AZPN spiked modestly higher here right off some near-term support at $37 with above-average volume. This stock has been trending sideways and consolidating for the last month, with shares moving between $36 on the downside and $39.02 on the upside. This spike higher on Wednesday is now starting to push shares of AZPN within range of triggering a breakout trade above the upper-end of its recent range. That breakout will hit if AZPN manages to take out some key overhead resistance levels at $38.42 to its 52-week high at $39.02 with high volume. Traders should now look for long-biased trades in AZPN as long as it's trending above support at $37 or at $36 and then once it sustains a move or close above those breakout levels with volume that's near or above 410,726 shares. If that breakout hits soon, then AZPN will set up to enter new 52-week-high territory, which is bullish technical price action. Some possible upside targets off that breakout are $45 to $47.