When insiders buy their own shares, pay attention. Insiders usually buy their own shares for one reason only: They think the stock is cheap and has huge upside.

One biotechnology player that insiders are active in right now is Bioverativ (BIVV) , which focuses on the research, development and commercialization of therapies for the treatment of hemophilia and other blood disorders.

Bioverativ has a market cap of $6.2 billion. This stock trades at a reasonable valuation, with a forward price-to-earnings ratio of 17.8 times. Its estimated growth rate for this year is 27.8%, and for next year it's pegged at 17%. This is a cash-rich company, since its total cash position is $358.7 million and its total debt is zero.

A director just bought 90,000 shares, or $5.03 million worth of stock, at $55.93 per share.

Bioverativ

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If you're bullish on Bioverativ, I would look for long-biased trades as long as this stock is trending above some near-term support at $54.10 or at $51.06, and then once it breaks out above its all-time high of $59.50 with volume near or above its three-month average of 1.32 million shares. Some possible upside targets off that breakout are $65 to $70, or even $75 a share.

Regeneron Pharmaceuticals

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Another biotechnology player that insiders are loading up on here is Regeneron Pharmaceuticals (REGN) - Get Report , which discovers, develops and commercializes medicines for the treatment of serious medical conditions.

Regeneron Pharmaceuticals has a market cap of $50.7 billion. This stock trades at a fair valuation, with a forward price-to-earnings of 31 times. Its estimated growth rate for this year is 11.8%, and for next year it's pegged at 21%. This is a cash-rich company, since its total cash position is $1.31 billion and its total debt is $707.61 million.

A beneficial owner just bought 136,050 shares, or $65.05 million worth of stock, at $466.38 to $484.04 per share.

If you're bullish on Regeneron Pharmaceuticals, I would look for long-biased trades if this stock is trending above its 20-day at $457.86 or above $440, and then once it breaks out above its 52-week high of $489 with volume near or above its three-month average of 957,940 shares. Some possible upside targets off that move are $500 to $520 a share.

Akamai Technologies

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One technology player insiders are jumping into here is Akamai Technologies (AKAM) - Get Report , which is engaged in providing cloud services for delivering, optimizing and securing content and business applications over the internet.

Akamai Technologies has a market cap of $8.4 billion. This stock trades at a fair valuation, with a forward price-to-earnings of 16.8 times. This is a cash-rich company, since its total cash position is $845.1 million and its total debt is $645.72 million.

The CEO just bought 21,196 shares, or $999,000 worth of stock, at $47.17 per share.

If you're in the bull camp on Akamai Technologies, I would look for long-biased trades if this stock is trending above its 52-week low of $46.91 and once it breaks out above resistance levels at $49.06 to $51, with volume near or above its three-month average of 2.50 million shares. Some possible upside targets off that breakout are its 50-day at $54.54 to $57 a share.

Chesapeake Energy

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Another energy player that insiders are in love with here is Chesapeake Energy (CHK) - Get Report , which produces natural gas, oil and natural gas liquids in the U.S.

Chesapeake Energy has a market cap of $4.3 billion. This stock trades at a cheap valuation, with forward price-to-earnings of 4.34 times. Its estimated growth rate for the next quarter is 122.2%, and for next year it's pegged at 31.4%. This is not a cash-rich company, since its total cash position is $249 million and its total debt is $9.52 billion.

A director just bought 75,000 shares, or $374,000 worth of stock, at $5 per share.

If you're bullish on Chesapeake Energy, I would look for long-biased trades if this stock is trending above its recent low of $4.79 or around $4, and then once it breaks out above $5 to $5.22 and over its 20-day at $5.37 to its 50-day at $5.56 with volume near or above its three-month average of 40.37 million shares. Some possible upside targets off that breakout are $5.90 to its 200-day at $6.20 a share.

Avnet

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My final stock with some large insider buying is services player Avnet (AVT) - Get Report , which distributes electronic components, enterprise computer, networking and storage products and software, and embedded subsystems.

Avnet has a market cap of $4.7 billion. This stock trades at a fair valuation, with a forward price-to-earnings 11.8 times. This is not a cash-rich company, since its total cash position is $1.39 billion and its total debt is $1.76 billion.

A director just bought 408,451 shares, or $15.10 million worth of stock, at $36.59 to $37.05 per share.

If you're bullish on Avnet, I would look for long-biased trades if this stock is trending above its recent low of $35.79 and then once it breaks out above resistance levels at $38 to $39 with volume near or above its three-month average of 1.43 million shares. Some possible upside targets off that breakout are its 50-day at $40.22 to its 200-day at $43.13, or even $45 a share.

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