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. Many times 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 Under $10 Set to Soar

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.

Let's take a look at

several stocks rising on unusual volume today

.

Saba Software

Saba Software

(SABA)

is a provider of learning and talent management solutions providing a set of People Cloud Applications that include enterprise learning, talent management, testing and assessment and collaboration solutions delivered through the Saba People Cloud. The stock is trading up 6.1% at $11.64 in recent trading.

Today's Volume: 755,000

Average Volume: 206,587

Volume % Change: 299%

From a technical perspective, SABA has now entered major breakout territory today with the stock solidly above some past overhead resistance at $10.62. This move has now pushed SABA into price levels not seen since 2003.

That said, the relative strength index (RSI) for SABA is now 84, which indicates a bought condition. It's probably best to let this stock work off those over bought conditions before getting long, if you're not in this stock.

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American Capital Mortgage Investment

American Capital Mortgage Investment

(MTGE)

was formed to invest in and manage a leveraged portfolio of agency mortgage investments, non-agency mortgage investments and other mortgage-related investments. The stock is trading up 4.3% at $20.60 in recent trading.

Today's Volume: 6230,000

Average Volume: 114,713

Volume % Change: 522%

From a

technical perspective

, MTGE are gapping up strong today on monster volume and breaking out above some past overhead

resistance

at $20. This breakout is pushing MTGE into all-time-high territory, which is bullish price action.

That said, the relative strength index (RSI) reading for MTGE is now 81.88 which indicates an overbought level. There's no doubt that this chart looks bullish, but I would let this consolidate some of those overbought conditions if you're not already long this stock.

MTGE is one of the

highest-yielding dividend stocks

; it currently yields 16.3%.

Whole Foods Market

Whole Foods Market

(WFM)

is a natural and organic foods supermarket. The stock is trading up 4.7% at $81.65 in recent trading.

Today's Volume: 5.7 million

Average Volume: 1.6 million

Volume % Change: 337%

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Shares of WFM are surging higher today on strong volume after the company reported a net income of $118.3 million on $3.4 billion in revenue in the first quarter, compared to a net income of $88.7 million on $3 billion in revenue during the same period last year.

From a technical perspective, WFM has triggered a major breakout today now that this stock has started to take out some near-term overhead resistance at $78.29 on huge volume. This is a very bullish move for WFM since it has now pushed the stock into all-time high territory. As long as WFM continues to tend above $78.28, then it has a great chance to make a run at $100 in the near future.

Whole Foods, which shows up on a list of

9 Rich-Kid Stocks Bucking the Terrible Economy

, was also featured in "

5 Consumer Stocks Funds Love

TheStreet Recommends

."

Focus Media

Focus Media

( FMCN) operates an interactive digital media network. The stock is trading up 4.8% at $24.58 in recent trading.

Today's Volume: 4.4 million

Average Volume: 5.6 million

Volume % Change: 56%

From a technical perspective, FMCN is starting to trigger a big breakout trade today now that this stock is moving above some near-term and past overhead resistance at 22.87 to $22.98 on decent volume.

Market players should now watch for FMCN to sustain a high-volume move and close above those levels to signal that it wants to trend much higher. Look for volume that's near or well above 5,595,800 shares. As long as FMCN closes near its daily highs today at 24.89, then target a move higher in the near-term back to its 200-day moving average of $26.72 or its next significant overhead resistance at $28.60.

Ironwood Pharmaceuticals

Ironwood Pharmaceuticals

(IRWD) - Get Ironwood Pharmaceuticals, Inc. Class A Report

is a pharmaceutical company that discovers and develops medicines. The stock is trading up 7.3% at $14.80 in recent trading.

Today's Volume: 888,000

Average Volume: 289,711

Volume % Change: 266%

Shares of IRWD are ripping higher today on strong volume after the company said that it was informed that the FDA will not schedule an advisory committee meeting in connection with the its review of the New Drug Application for linaclotide.

From a technical perspective, IRWD is ripping higher today on monster volume and the stock is quickly approaching a breakout trade if it can manage to clear some near-term overhead resistance.

Traders should look for a sustained high-volume move and close above $15.67 to signal that this stock wants to trend much higher. Look for volume on a move above that level that's near or above 289,711 shares. If we get that action soon, then I would target a move back towards some major past resistance at $16.50.

NxStage Medical

NxStage Medical

(NXTM) - Get NxStage Medical, Inc. Report

is a medical device company that develops, manufactures and markets products for the treatment of kidney failure, fluid overload and related blood treatments and procedures. This stock is trading up 3.9% at $21.01 in recent trading.

Today's Volume: 991,000

Average Volume: 512,889

Volume % Change: 93%

From a technical perspective, NXTM has started to trigger a major breakout trade today now that this stock is moving above some past overhead resistance at $20.05 to $20.13 on heavy volume.

Traders should continue to look for long biased trades in NXTM as long as the stock can continue to trend above those key breakout levels. I would target a run back towards the next significant overhead resistance at $24 in the near future, if those breakout levels hold.

Responsys

Responsys

(MKTG)

is a provider of on-demand software and professional services. The stock is trading up 5.2% at $11.89 in recent trading.

Today's Volume: 682,000

Average Volume: 273,227

Volume % Change: 317%

From a technical perspective, MKTG is getting very close to triggering a major breakout trade today if this stock can manage to take out some near-term overhead resistance.

Traders should now watch for MKTG to sustain a high-volume move and close above $11.94 to signal that it wants to trend much higher. At last check, the volume is monster and the high of the day is $11.99. If we get that high-volume move and close soon, then target a run towards $14 in the near future.

To see more stocks rising on unusual volume, check out the

Stocks Rising On Unusual Volume

portfolio on Stockpickr.

-- Written by Roberto Pedone in Winderemere, Fla.

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At the time of publication, author had no positions in stocks mentioned.

Roberto Pedone, based out of Windermere, Fla., is an independent trader who focuses on stocks, options, futures, commodities and currencies. He is also an outside contributor to Beconequity.com and maintains the website Maddmoney.net, which he sold to Blue Wave Advisors in 2008. Roberto studied International Business at The Milwaukee School of Engineering, and he spent a year overseas studying business in Lubeck, Germany.