Insider buying in the open market is generally 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. Also, 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 at least one insider make an open market buy in the last 30 days. Here are 11 stocks in the materials sector that made the list:

Stock

Net Number of Buys

 

No. of Shares Bought

Total Value

Market Cap (in millions)

Texas Industries 4 753,592 $29,870,000 $1,107
AbitibiBowater 1 442,100 $10,050,000 $2,137
Valhi (NYSE: VHI) 18 111,673 $4,640,000 $5,156
Yongye International (Nasdaq: YONG) 2 555,000 $3,000,000 $256
Kraton Performance Polymers 2 30,000 $1,160,000 $1,196
Mercer International (Nasdaq: MERC) 9 77,000 $512,000 $523
Zoltek Companies (Nasdaq: ZOLT) 3 17,574 $180,000 $341
Coeur d'Alene Mines (NYSE: CDE) 2 5,000 $132,000 $2,203
Myers Industries (NYSE: MYE) 5 6,000 $59,000 $363
PH Glatfelter 1 4,000 $58,000 $694
Flotek Industries (NYSE: FTK) 2 59,861 $41,000 $392

Source: Capital IQ, a division of Standard & Poor's, as of June 21.

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 four open-market purchases of Texas Industries totaling almost $30 million, compared with one open-market purchase of PH Glatfelter totaling $58,000. Both are bullish signs, but the Texas Industries sign is more likely to be marking 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. 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.