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 two semiconductor stocks made the list:

Security

Net Number of Buys

No. of Shares Bought

Total Value

Market Cap (in millions)

Sigma Designs (Nasdaq: SIGM) 4 35,000 $278,000 $275
Microchip Technology (Nasdaq: MCHP) 1 200 $7,000 $7,214

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

When it comes to the number and total value of insider open market buys, more can be better; I've sorted this table accordingly. The size of the Microchip Technology insider buy looks a lot more promising than the Sigma Designs insider buys. That said, they are nowhere near the size of the STEC (Nasdaq: STEC) purchases that showed up when I ran the same screen a month ago:

Security

Net Number of Buys

No. of Shares Bought

Total Value

Market Cap (in millions)

STEC 2 438,019 $6,420,000 $853
MEMC Electronic Materials (NYSE: WFR) 1 3,000 $30,000 $2,187

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

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 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. 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.