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.

Murphy USA

One specialty retailer that insiders are active in here is Murphy USA (MUSA - Get Report) , which operates a chain of retail stores in the U.S. Insiders are buying this stock into notable weakness, since shares have fallen by 15.7% over the last six months.

Murphy USA has a market cap of $2.5 billion and an enterprise value of $2.9 billion. This stock trades at a cheap valuation, with a trailing price-to-earnings of 11.7 and a forward price-to-earnings of 12.6. Its estimated growth rate for this year is 10.2%, and for next year it's pegged at 11.6%. This is not a cash-rich company, since the total cash position on its balance sheet is $153.81 million and its total debt is $670.22 million.

A director just bought 15,000 shares, or about $980,000 worth of stock, at $65.39 per share.

From a technical perspective, Murphy USA is currently trending above its 50-day moving average and below its 200-day moving average, which is neutral trendwise. This stock has been uptrending over the last month and change, with shares moving higher off its low of $60.44 a share to its recent high of $68.83 a share. During that uptrend, shares of Murphy USA have been making mostly higher lows and higher highs, which is bullish technical price action.

If you're bullish on Murphy USA then I would look for long-biased trades as long as this stock is trending above either its 50-day moving average of $64.88 a share or its 20-day moving average of $63.76 a share and then once it breaks out above some near-term overhead resistance levels at $67 to $68 a share and above its 200-day moving average of $69.08 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 507,244 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 $70.50 to $71.50, or even $73 to $75 a share.

Ciber

Another technology player that insiders are jumping into here is Ciber (CBR) , which operates as an information technology (IT) service company worldwide. Insiders are buying this stock into massive weakness, since shares have plunged by 63% over the last six months.

Ciber has a market cap of $31 million and an enterprise value of $60.6 million. This stock trades at a fair valuation, with a price-to-sales of 0.04 and a price-to-book of 0.17. Its estimated growth rate for this year is -870%, and for next year it's pegged at 58.4%. This is not a cash-rich company, since the total cash position on its balance sheet is $6.43 million and its total debt is $39.37 million.

A director just bought 2,428,705 shares, or about $741,000 worth of stock, at 28 to 33 cents per share.

From a technical perspective, Ciber is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock recently plunged sharply lower from 70 cents per share to its new 52-week low of 22 cents per share. Following that collapse, shares of Ciber have now started to rebound sharply higher off that 22 cents per share low to its intraday high on Wednesday of 43 cents per share with strong upside volume flows.

If you're bullish on Ciber then I would look for long-biased trades as long as this stock is trending above some key near-term support at 30 cents per share and then once it breaks out above some near-term overhead resistance levels at 43 to 47 cents per share with strong volume. Look for a sustained move or close above those levels with volume that hits near or above its three-month average action of 1.02 million 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 its 20-day moving average of 52 cents per share to 60 cents, or even its 50-day moving average of 66 cents per share to 70 cents per share.

Qualcomm

One technology player that insiders are snapping up here is Qualcomm (QCOM - Get Report) , which develops, designs, manufactures, and markets digital communications products and services in China, South Korea, Taiwan, the U.S., and internationally. Insiders are buying this stock into big weakness, since shares have dropped by 22.5% over the last three months.

Qualcomm has a market cap of $78 billion and an enterprise value of $79 billion. This stock trades at a fair valuation, with a trailing price-to-earnings of 16 and a forward price-to-earnings of 11. Its estimated growth rate for this year is 5.4%, and for next year it's pegged at 2.6%. This is not a cash-rich company, since the total cash position on its balance sheet is $10.81 billion and its total debt is $11.68 billion. This stock currently sports a dividend yield of 4%.

The vice president just bought 18,815 shares, or about $999,000 worth of stock, at $53.13 per share.

From a technical perspective, Qualcomm is currently trending below both its 50-day and 200-day moving averages, which is bearish. This stock recently gapped-down sharply lower from around $66 a share to under $54 a share with monster downside volume. Following that move, shares of Qualcomm have now started to trend sideways a bit between $52.37 a share and $54 a share. Any high-volume move above the upper-end of that recent sideways trending chart pattern could trigger a near-term breakout trade for shares of Qualcomm.

If you're in the bull camp on Qualcomm, then I would look for long-biased trades as long as this stock is trending above that recent low of $52.37 a share and then once it breaks out above some near-term overhead resistance levels at $54 to $55 a share with volume that hits near or above its three-month average action of 12 million 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 $57 to its 20-day moving average of $57.79 a share, or even $59 a share.

Abbott Laboratories

One healthcare player that insiders are in love with here is Abbott Laboratories (ABT - Get Report) , which manufactures and sells health care products worldwide. Insiders are buying this stock into modest weakness, since shares have dropped by 5.5% over the last six months.

Abbott Laboratories has a market cap of $73 billion and an enterprise value of $67 billion. This stock trades at a fair valuation, with a trailing price-to-earnings of 45.3 and a forward price-to-earnings of 15.4. Its estimated growth rate for this year is 11.4%, and for next year it's pegged at 12.2%. This is not a cash-rich company, since the total cash position on its balance sheet is $4.51 billion and its total debt is $8.51 billion. This stock currently sports a dividend yield of 2.4%.

A vice president just bought 12,200 shares, or about $497,000 worth of stock, at $40.77 per share.

From a technical perspective, Abbott Laboratories 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 two months and change, with shares moving higher off its low of $37.14 a share to its recent high of $43.13 a share. During that uptrend, shares of Abbott Laboratories have been making mostly higher lows and higher highs, which is bullish technical price action. That trend to the upside is now quickly pushing this stock within range of triggering a near-term breakout trade above some key overhead resistance levels.

If you're bullish on Abbott Laboratories, then I would look for long-biased trades as long as this stock is trending above its 20-day moving average of $41.33 a share or above its 50-day moving average of $39.68 a share and then once it breaks out above some near-term overhead resistance levels at $43.13 to $43.22 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 9.44 million 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 $45.20 to its 52-week high of $45.79 a share, or even $47 to $49 a share.

Tailored Brands

My final stock with some monster insider buying is men's apparel player Tailored Brands (TLRD - Get Report) , which operates as a specialty apparel retailer in the U.S., Puerto Rico, and Canada. Insiders are buying this stock into massive strength, since shares have ripped higher by 47.1% over the last six months.

Tailored Brands has a market cap of $1.03 billion and an enterprise value of $2.5 billion. This stock trades at a reasonable valuation, with a forward price-to-earnings of 10. Its estimated growth rate for this year is 1.7%, and for next year its pegged at 13.7%. This is not a cash-rich company, since the total cash position on its balance sheet is $34.95 million and its total debt is $1.60 billion. This stock currently sports a dividend yield of 3.3%.

A beneficial owner just bought 1,110,000 shares, or about $22.20 million worth of stock, at $20 per share.

From a technical perspective, Tailored Brands is currently trending above its 200-day moving average and below its 50-day moving average, which is neutral trendwise. This stock recently formed a double bottom chart pattern, after shares found some buying interest at $19.75 to $19.17 a share over the last month. Following that potential bottom, shares of Tailored Brands have now started to trend higher and flirt with its 20-day moving average of $20.97 a share. That bump to the upside is now quickly pushing this stock within range of triggering a big breakout trade above some key overhead resistance levels.

If you're bullish on Tailored Brands, then I would look for long-biased trades as long as this stock is trending above those recent double bottom support levels and then once it breaks out above some near-term overhead resistance levels at $22 to $22.50 a share and then above its 50-day moving average of $22.70 a share to $23 a share with volume that registers near or above its three-month average action of 1.62 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 $26 to $27, or even its 52-week high of $28.76 a share.

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