Insider buying in the open market is generally considered a bullish indicator, as corporate insiders often have the inside track on the company's prospects and 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.

Although 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 that 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 past 30 days. Here are 11 health-care stocks that made the list.

Security

Net Number of Buys

No. of Shares Bought

Total Value

Market Cap (Millions)

China Biologic Products (Nasdaq: CBPO) 3 582,057 $9,290,000 $242
Opko Health (AMEX: OPK) 13 469,413 $1,660,000 $969
Medtronic (NYSE: MDT) 1 450,757 $1,020,000 $41,148
Valeant Pharmaceuticals International (NYSE: VRX) 12 82,671 $508,000 $14,936
PROLOR Biotech 2 30,852 $144,000 $242
ArQule 6 30,580 $186,000 $355
Fluidigm 1 29,700 $424,000 $280
Boston Scientific (NYSE: BSX) 1 26,500 $66,000 $10,438
GTX (Nasdaq: GTXI) 1 16,050 $101,000 $282
Meridian Bioscience 2 15,625 $237,000 $981
Cytori Therapeutics (Nasdaq: CYTX) 1 1,500 $8,000 $251

Source: Capital IQ, a division of Standard & Poor's, as of 6/16/11.

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 three open-market purchases of Opko Health totaling almost $1.7 million, compared with one open-market purchase of Cytori Therapeutics totaling $8,000. Both are bullish signs, but the Opko Health transaction 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: