DELAFIELD, Wis. (Stockpickr) -- 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.

New Media Investment Group

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One publishing player that insiders are loading up on here is New Media Investment Group (NEWM - Get Report), which owns, operates, and invests in local media assets in the U.S. Insiders are buying this stock into notable weakness, since shares have slid lower by 18.5% over the last three months.

New Media Investment Group has a market cap of $808 million and an enterprise value of $1.1 billion. This stock trades at a cheap valuation, with a forward price-to-earnings of 11.5. Its estimated growth rate for this year is 980%, and for next year it's pegged at 78.4%. This is not a cash-rich company, since the total cash position on its balance sheet is $26.93 million and its total debt is $362.73 million. This stock currently sports a dividend yield of 7.7%.

A beneficial owner just bought 120,623 shares, or about $2.05 million worth of stock, at $17.01 per share.

From a technical perspective, New Media Investment Group is currently trending well below both its 50-day and 200-day moving averages, which is bearish. This stock has recently started to rebound sharply higher right off its recent low of $16.84 a share with strong upside volume flows. That rebound is coming after a nasty downtrend that took shares New Media Investment Group lower from its March high of $25.05 to that recent low of $16.84 a share. Shares of New Media Investment Group are now quickly moving within range of triggering a near-term breakout trade above some key overhead resistance levels.

If you're bullish on New Media Investment Group, then I would look for long-biased trades as long as this stock is trending above some near-term support levels at $17.50 or above that recent low of $16.84 a share and then once it breaks out above some near-term overhead resistance levels at $18.38 to $19.31 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 400,868 shares. If that breakout materializes 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 $20.08 to its 200-day moving average of $20.73 a share, or even $22.50 to $23 a share.

Energy Transfer Equity

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Another energy player that insiders are snapping up a huge amount of stock in here is Energy Transfer Equity (ETE), which owns and operates approximately 7,700 miles of natural gas transportation pipelines and 3 natural gas storage facilities located in the state of Texas; and approximately 12,800 miles of interstate natural gas pipeline. Insiders are buying this stock into large strength, since shares have ripped higher by 26% over the last six months.

Energy Transfer Equity has a market cap of $35.3 billion and an enterprise value of $66.8 billion. This stock trades at a reasonable valuation, with a trailing price-to-earnings of 47.3 and a forward price-to-earnings of 22.2. Its estimated growth rate for this year is 100.9%, and for next year it's pegged at 27.9%. This is not a cash-rich company, since the total cash position on its balance sheet is $1.86 billion and its total debt is $33.43 billion. This stock currently sports a dividend yield of 3%.

A director just bought 1,000,000 shares, or about $63.04 million worth of stock, at $62.63 to $62.95 per share.

From a technical perspective, Energy Transfer Equity is currently trending below its 50-day moving average and above its 200-day moving average, which is neutral trendwise. This stock recently spiked sharply higher right above its 200-day moving average with decent upside volume flows. That spike is now starting to push shares of Energy Transfer Equity within range of triggering a near-term breakout trade above some key overhead resistance levels.

If you're in the bull camp on Energy Transfer Equity, then I would look for long-biased trades as long as this stock is trending above some near-term support levels at $64 or at $63 a share and then once it breaks out above some near-term overhead resistance levels at $66.11 to its 50-day moving average of $67.13 a share with volume that hits near or above its three-month average action of 1.88 million shares. If that breakout kicks off soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $70 to its 52-week high of $70.88 a share, or even $75 a share.

Layne Christensen

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One heavy construction player that insiders are jumping into here is Layne Christensen (LAYN), which provides water management, construction, and drilling services in North America and internationally. Insiders are buying this stock into massive strength, since shares have exploded higher by 79.3% over the last three months.

Layne Christensen has a market cap of $182 million and an enterprise value of $272 million. This stock trades at a reasonable valuation, with a forward price-to-earnings of 46.4. Its estimated growth rate for this year is 85.2%, and for next year it's pegged at 139.2%. This is not a cash-rich company, since the total cash position on its balance sheet is $56.61 million and its total debt is $161.89 million.

A director just bought 67,315 shares, or about $555,000 worth of stock, at $8.26 to $8.30 per share. That same director also just bought 37,000 shares, or about $304,000 worth of stock, at $8.23 per share.

From a technical perspective, Layne Christensen is currently trending above both its 50-day and 200-day moving averages, which is bullish. This stock has been uptrending strong over the last five months, with shares soaring higher from its low of $4.35 to its recent high of $10.50 a share. During that uptrend, shares of Layne Christensen have been making mostly higher lows and higher highs, which is bullish technical price action.

If you're bullish on Layne Christensen, then I would look for long-biased trades as long as this stock is trending above its 50-day at $8.61 or above its 200-day at $7.70 a share and then once it breaks out above some near-term overhead resistance levels at $9.75 to $10.50 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 385,378 shares. If that breakout gets started soon, then shares of Layne Christensen will set up to re-test or possibly take out its next major overhead resistance levels at $12 to its 52-week high of $12.66 a share.

Xerium Technologies

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One industrial goods player that insiders are active in here is Xerium Technologies (XRM), which manufactures and supplies consumable products primarily used in the production of paper. Insiders are buying this stock into notable strength, since shares have trended higher by 21.8% over the last six months.

Xerium Technologies has a market cap of $284 million and an enterprise value of $747 million. This stock trades at a cheap valuation, with a forward price-to-earnings of 9. Its estimated growth rate for this year is 134.4%, and for next year it's pegged at 40.6%. This is not a cash-rich company, since the total cash position on its balance sheet is $8.83 million and its total debt is $473.57 million.

A beneficial owner just bought 14,350 shares, or about $256,000 worth of stock, at $17.86 to $17.91 per share. That same beneficial owner also just bought 7,500 shares, or about $133,000 worth of stock, at $17.73 per share.

From a technical perspective, Xerium Technologies is currently trending above both its 50-day and 200-day moving averages, which is bullish. This stock has been uptrending over the last month and change, with shares moving higher from its low of $16.69 to its recent high of $18.80 a share. During that uptrend, this stock has been making mostly higher lows and higher highs, which is bullish technical price action.

If you're bullish on Xerium Technologies, then I would look for long-biased trades as long as this stock is trending above some near-term support at $17.57 a share and then once it breaks out above some key near-term overhead resistance levels at $18.80 to its 52-week high of $18.93 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 32,257 shares. If that breakout develops soon, then shares of Xerium Technologies will set up to enter new 52-week-high territory, which is bullish technical price action. Some possible upside targets off that move are $20 to $22, or even $24 a share.

Cadiz

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One final stock with some decent insider buying is Cadiz (CDZI - Get Report), which operates as a land and water resource development company in the U.S. Insiders are buying this stock into modest weakness, since shares have dropped by 7.3% over the last six months.

Cadiz has a market cap of $170 million and an enterprise value of $258 million. This stock trades at a premium valuation, with a price-to-sales of 477.54. This is not a cash-rich company, since the total cash position on its balance sheet is $13.55 million and its total debt is $106.53 million.

A beneficial owner just bought 30,000 shares, or about $283,000 worth of stock, at $9.41 to $9.47 per share.

From a technical perspective, Cadiz is currently trending above its 50-day moving average and just below is 200-day moving average, which is neutral trendwise. This stock has been uptrending for the last two months and change, with shares moving higher from its low of $6.88 to its recent high of $10.50 a share. During that uptrend, shares of Cadiz have been making mostly higher lows and higher highs, which is bullish technical price action. That move has now pushed shares of Cadiz within range of triggering a near-term breakout trade.

If you're bullish on Cadiz, then I would look for long-biased trades as long as this stock is trending above some near-term support at $8.99 or above its 50-day at $8.45 and then once it breaks out above some near-term overhead resistance levels at $9.75 to its 200-day moving average of $9.80 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 volume of 151,671 shares. If that breakout hits soon, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $10.50 to $10.80 a share, or even $11 to $11.50 a share.

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