Insider buying in the open market generally is considered a bullish indicator. Corporate insiders often have the inside track on the company's prospects. What's more, their income is typically closely tied to their company's stock. Often a big chunk of that income is in the form of stock options or restricted stock. What's more, diversification argues for minimizing exposure to any one company rather than adding to it with insider buys.

While insider selling may indicate nothing more than a college tuition bill coming due, a home remodeling, or a high-end vacation, buying is typically a sign the insider expects the stock to rise. Buying in the open market could be considered more bullish than exercising stock options because the insider found some other way to fund the purchase.

With that in mind, I ran a screen to find companies that have had open market insider buys totaling at least $50,000 in the last 30 days. Here are 12 industrial stocks that made the list:

Security

Net Number of Buys

No.  of Shares Bought

Total Value

Market Cap

($million)

Swisher Hygiene (Nasdaq: SWSH)

 2

 107,370

 $609,000

 $956

DXP Enterprises (Nasdaq: DXPE)

 1

 12,700

 $309,000

 $337

Patriot Transportation Holding

 3

 11,694

 $254,000

 $219

SeaCube Container Leasing

 1

 11,000

 $200,000

 $334

Accuride

 2

 15,000

 $197,000

 $587

CDI

 1

 10,000

 $134,000

 $258

Fastenal (Nasdaq: FAST)

 1

 3,400

 $111,000

 $9,885

TASER International (Nasdaq: TASR)

 1

 25,000

 $108,000

 $260

Emerson Electric (NYSE: EMR)

 1

 2,000

 $105,000

 $40,139

Tennant

 1

 2,800

 $99,000

 $744

Eaton (NYSE: ETN)

 1

 2,000

 $93,000

 $16,507

Hill International (NYSE: HIL)

 7

 15,161

 $62,000

 $202

Source: Capital IQ, a division of Standard & Poor's, as of 6/22/11.

When it comes to the number and total value of insider open-market buys, more could be considered better. The table is sorted accordingly. For example, there were two open-market purchases of Swisher Hygiene totaling $600,009 compared with one open-market purchase of Eaton totaling $93,000. Both are bullish signs, but the Swisher Hygiene sign more likely marks an on-ramp you want to take.

Foolish takeaway
Insider buying is a sign that someone who should be in the know is betting that the stock is going to rise. You can use this list of open-market insider purchases in the past 30 days to generate research ideas and/or reinforce a contrarian view.

Are these insiders right? To help you find out, the Motley Fool recently introduced a free My Watchlist feature. You can get up-to-date news and analysis by adding companies to your Watchlist now:

Fool contributor Cindy Johnson does not currently own shares of any stock in this story. Motley Fool newsletter services have recommended buying shares of Emerson Electric and Tennant. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.