Corporate insiders sell their own companies' stock for a number of reasons. ¿

They might need the cash for a big personal purchase such as a new house or yacht, or they might need the cash to fund a charity. Sometimes they sell as part of a planned selling program that they have put in place for diversification purposes, which allows them to sell stock in stages instead of selling all at one price.

Other times they sell because they think their stock is overvalued and the risk/reward is no longer attractive. Some even dump their own stock because they have inside knowledge that a competitor is eating their lunch and stealing market share. ¿

But insiders usually buy their own shares for one reason: They think the stock is a bargain and has tremendous upside.

The key word in that last statement is "think." Just because a corporate insider thinks his or her stock is going to trade higher, that doesn't mean it will play out that way. Insiders can have all the conviction in the world that their stock is a buy, but if the market doesn't agree with them, the stock could end up going nowhere. Also, I say "usually" because sometimes insiders are loaned money by the company to buy their own stock. Those loans are often sweetheart deals and shouldn't be viewed as organic insider buying.

At the end of the day, it's institutional money managers running big mutual funds and hedge funds that drive stock prices, not insiders. That said, many of these savvy stock operators will follow insider buying activity when they agree with the insider that the stock is undervalued and has upside potential. This is why it's so important to always be monitoring insider activity but twice as important to make sure the trend of the stock coincides with the insider buying.

Recently, a number of companies' corporate insiders have bought large amounts of stock. These insiders are finding some value in the market, which warrants a closer look at these stocks.

Ascena Retail Group

One stock that insiders are active in here is Ascena Retail Group(ASNA) - Get Report , which operates as a specialty retailer of clothing, shoes and accessories for women and girls in the U.S., Canada and Puerto Rico. Insiders are buying this stock into large weakness, since shares have plunged by 41% over the last six months.

Ascena Retail Group has a market cap of $1.9 billion and an enterprise value of $3.3 billion. This stock trades at a cheap valuation, with a forward price-to-earnings of 10.3. Its estimated growth rate for this year is 32.2%, and for next year it's pegged at 25.6%. This is not a cash-rich company, since the total cash position on its balance sheet is $323.60 million and its total debt is $1.81 billion.

The chairman of the board just bought 100,000 shares, or about $969,000 worth of stock, at $9.68 per share.

From a technical perspective, Ascena Retail Group is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock has recently started to spike higher right above its new 52-week low of $9.52 a share. That spike is starting to push shares of Ascena Retail Group within range of triggering a near-term breakout trade above some key overhead resistance levels.

If you're bullish on Ascena Retail Group, then I would look for long-biased trades as long as this stock is trending above its new 52-week low of $9.52 a share and then once it breaks out above some near-term overhead resistance levels at $10.43 to its 20-day moving average of $10.61 a share with high volume. Look for a sustained move or close above those levels with volume that hits near or above its three-month average action of 4.35 million shares. If that breakout triggers soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at its 50-day moving average of $11.68 to $12.85 a share.

comScore

Another stock that insider are in love with here is comScore(SCOR) - Get Report , which provides digital media analytics products and services for content publishers, advertisers, advertising agencies and network operators primarily in the U.S., Canada, Europe, Latin America and Asia. Insiders are buying this stock into notable weakness, since shares have dropped sharply by 28.8% over the last six months.

comScore has a market cap of $1.5 billion and an enterprise value of $1.4 billion. This stock trades at a premium valuation, with a forward price-to-earnings of 110. Its estimated growth rate for this year is 3.4%, and for next year it's pegged at 228.6%. This is a cash-rich company, since the total cash position on its balance sheet is $141.83 million and its total debt is $31.05 million.

A beneficial owner just bought 120,000 shares, or about $4.62 million worth of stock, at $38.40 per share.

From a technical perspective, comScore is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock has been downtrending badly over the last three months and change, with shares falling sharply lower off its high of $51.37 to its new 52-week low of $36.91 a share. During that downtrend, shares of comScore have been making mostly lower highs and lower lows, which is bearish technical price action. That said, this stock has now started to bounce higher off that $36.91 low and it's quickly moving within range of triggering a near-term breakout trade.

If you're in the bull camp on comScore, then I would look for long-biased trades as long as this stock is trending above its new 52-week low of $36.91 a share and then once it breaks out above some near-term overhead resistance levels at $40 a share to its 20-day moving average of $40.90 a share with volume that registers near or above its three-month average action of 433,533 shares. If that breakout gets started soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at its 50-day moving average of $42.64 to $45.21, or even $46.66 to $50 a share.

Dominion Midstream Partners

One energy stock that insiders are jumping into here is Dominion Midstream Partners (DM) , which owns liquefied natural gas import, storage, regasification and transportation assets. Insiders are buying this stock into notable weakness, since shares have dropped sharply lower by 28.8% over the last six months.

Dominion Midstream Partners has a market cap of $2.2 billion and an enterprise value of $2.4 billion. This stock trades at a reasonable valuation, with a forward price-to-earnings of 23.4. Its estimated growth rate for this year is 573.3%, and for next year it's pegged at 22.8%. This is not a cash-rich company, since the total cash position on its balance sheet is $107 million and its total debt is $306.70 million. This stock currently sports a dividend yield of 2.9%.

A director just bought 41,915 shares, or about $1.15 million worth of stock, at $27.24 to $27.87 per share. That same director also just bought 50,000 shares, or about $1.33 million worth of stock, at $26.29 to $26.64 per share.

From a technical perspective, Dominion Midstream Partners is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock recently formed a double bottom chart pattern, after shares found some buying interest at $26 to $25.64 a share. Following that bottom, shares of Dominion Midstream Partners have now started to spike higher back above its 20-day moving average of $28.76 a share, and it's quickly moving within range of triggering a near-term breakout trade.

If you're bullish on Dominion Midstream Partners, then I would look for long-biased trades as long as this stock is trending above some near-term support levels at $27 or at $25.64 a share and then once it breaks out above some near-term overhead resistance levels at its 50-day moving average of $30.57 to $30.58 a share with high volume. Look for a sustained move or close above those levels with volume that hits near or above its three-month average action of 202,502 shares. If that breakout fires off soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $32.55 to $33.69, or even $34.86 to its 200-day moving average of $34.90 a share.

Guidance Software

Another stock that insiders are active in here is Guidance Software (GUID) , which provides digital investigative solutions in the U.S., Europe, Asia and internationally. Insiders are buying this stock into large weakness, since shares have dropped by 36.8% over the last six months.

Guidance Software has a market cap of $173 million and an enterprise value of $141 million. This stock trades at a premium valuation, with a price-to-sales of 1.44 and a price-to-book of 11.73. Its estimated growth rate for this year is -140%, and for next year it's pegged at 41.7%. This is a cash-rich company, since the total cash position on its balance sheet is $18 million and its total debt is just $70,000.

A beneficial owner just bought 340,000 shares, or about $1.78 million worth of stock, at $5.25 per share.

From a technical perspective, Guidance Software is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock has been uptrending a bit over the last few weeks, with shares moving higher off its new 52-week low of $4.70 a share to its intraday high on Tuesday of $5.68 a share. During that uptrend, shares of Guidance Software have been consistently making higher lows and higher highs, which is bullish technical price action. That move has now pushed this stock within range of triggering a near-term breakout trade above some key overhead resistance levels.

If you're bullish on Guidance Software, then I would look for long-biased trades as long as this stock is trending above some near-term support at $5.25 a share and then once it breaks out above some near-term overhead resistance levels at its 20-day moving average of $5.72 to its 50-day moving average of $5.85 a share with high volume. Look for a sustained move or close above those levels with volume that registers near or above its three-month average action of 91,059 shares. If that breakout develops soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $6.23 to its 200-day moving average of $6.89, or even $7.50 a share.

Summit Midstream Partners

One final stock with some large insider buying is energy player Summit Midstream Partners(SMLP) - Get Report , which focuses on owning, developing and operating midstream energy infrastructure assets primarily shale formations, in North America. Insiders are buying this stock into massive weakness, since shares have plunged by 46.5% over the last six months.

Summit Midstream Partners has a market cap of $1.1 billion and an enterprise value of $2 billion. This stock trades at a reasonable valuation, with a forward price-to-earnings of 21.1. Its estimated growth rate for next year is -3.4, and for next year it's pegged at 45.6%. This is not a cash-rich company, since the total cash position on its balance sheet is $5.46 million and its total debt is $904.64 million. This stock currently sports a dividend yield of 15%.

A director just bought 75,883 shares, or about $1.20 million worth of stock at $15.86 to $16.59 per share. That same director also just bought 75,277 shares, or about $1.20 million worth of stock at $16.05 per share. From a technical perspective, Summit Midstream Partners is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock has been uptrending over the last month, with shares ripping higher off its new 52-week low of $12.82 a share to its intraday high on Tuesday of $18.121 a share. During that uptrend, shares of Summit Midstream Partners have been making mostly higher lows and higher highs, which is bullish technical price action. That move has now pushed this stock within range of triggering a near-term breakout trade.

If you're bullish on Summit Midstream Partners, then I would look for long-biased trades as long as this stock is trending above some near-term support at $15 a share and then once it breaks out above some near-term overhead resistance levels at $19.50 to $20 a share and then above more key resistance at $20.65 a share with high volume. Look for a sustained move or close above those levels with volume that hits near or above its three-month average volume of 338,217 shares. If that breakout gets underway soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $22.58 to $23.50, or even $24.85 to its 200-day moving average of $25.12 a share.

Disclosure: This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.