When insiders buy shares on the open market, their companies could enjoy bullish times ahead. Corporate insiders often have the inside track on their companies' prospects, and many of them get paid largely in stock options or restricted shares. Besides, insiders probably wouldn't risk plowing too much of their own money into their own company's stock -- reducing their portfolio's diversity and increasing its risk -- unless they thought the stock might rise.

With that in mind, I screened for companies where at least one insider made an open-market buy in the last 30 days. These four computer hardware and equipment stocks made the list:

Security

Net Number of Buys

No.  of Shares Bought

Total Value

Market Cap (in millions)

Comtech Telecommunications (Nasdaq: CMTL)

 4

 23,315

 $557,000

 $770

Checkpoint Systems (NYSE: CKP)

 7

 19,325

 $199,000

 $714

Lexmark International (NYSE: LXK)

 5

 7,334

 $21,000

 $2,319

Methode Electronics (NYSE: MEI)

 1

 2,150

 $23,000

 $408

Source: Capital IQ, a division of Standard & Poor's, as of July 8, 2011.

When it comes to the number and total value of insider open-market buys, more can be better; I've sorted this table accordingly. Insiders at Comtech Telecommunications made four open-market purchases worth more than $500,000, while a Methode Electronics insider spent just $23,000 on a single open-market buy. Both are bullish signs, but the Comtech purchases look a lot more promising. And here's how insider buying over the last 30 days compares to results when I ran the same screen a month ago:

Security

Net Number of Buys

No.  of Shares Bought

Total Value

Market Cap (in millions)

TiVo (Nasdaq: TIVO)

1

10,000

$101,000

$1,237

Cisco Systems (Nasdaq: CSCO)

1

3,700

$60,000

$85,308

Source: Capital IQ, a division of Standard & Poor's, as of June 7, 2011.

Foolish takeaway
Insider buying signals that someone who should be in the know is betting that the stock will rise. You can use this list of recent insider purchases as a starting point for further research -- or a good reason to make a contrarian play.

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. The Fool owns shares of and has created a bull call spread position on Cisco Systems. Motley Fool newsletter services have recommended buying shares of Cisco Systems. 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.