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 Ready to Break Out 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 Set to Soar on Bullish Earnings BHP Billiton BHP Billiton ( BBL) is engaged in minerals exploration, development, production and processing, and oil and gas exploration, development and production. This stock is trading up 1.1% at $63.36 in recent trading. Today's Volume: 619,000 Average Volume: 531,748 Volume % Change: 97% From a technical perspective, BBL is trending higher here right above some near-term support at $62 with above-average volume. This move is quickly pushing shares of BBL within range of triggering a near-term breakout trade, which will hit if BBL manages to clear some near-term overhead resistance at $63.58 with high volume. Traders should now look for long-biased trades in BBL as long as it's trending above $62, and then once it sustains a move or close above $63.58 with volume that hits near or above 531,748 shares. If that breakout hits soon, then BBL will set up to re-test or possibly take out its next major overhead resistance levels at $65 to its 50-day moving average of $65.77. Any high-volume move above its 50-day will then put $68 to $68.31 into range for shares of BBL. Medicines Medicines ( MDCO) is a global biopharmaceutical company that treats critical care patients through the delivery of innovative, cost-effective medicines to the worldwide hospital marketplace. This stock is trading up 2% at $32.35 in recent trading.