Who knows the most about a company? You might answer, its insiders. In fact, company insiders report when they buy or sell company shares, giving a look into how they feel about their employer's prospects. When they're buying up company shares, analysts look at it very positively.

To illustrate this, we ran a screen on the clean energy industry -- companies that use or produce clean sources of energy -- for those with the most significant net insider purchases over the last six months. This indicates that insiders at these companies are optimistic about their employers.

Conversely, companies seeing net selling from company insiders may be viewed bearishly by the market.

Business section: Investing ideas
Below are the results of this screen -- these clean energy stocks have seen net buying from company insiders over the last six months, indicating their confidence in their employers.

Do you think these stocks are poised to outperform?

Use this list as a starting point for your own analysis. (Click here to access free, interactive tools to analyze these ideas.)

1. Federal Signal (NYSE: FSS): Designs and manufactures a suite of products and integrated solutions for municipal, governmental, industrial, and commercial customers worldwide. Over the last six months, insiders were net buyers of 79,500 shares, which represents about 0.13% of the company's 60.05M share float.

2. Republic Services (NYSE: RSG): Provides nonhazardous solid waste collection, transfer, and disposal services in the United States. Over the last six months, insiders were net buyers of 7,694,475 shares, which represents about 2.53% of the company's 303.85M share float.

3. MEMC Electronic Materials (NYSE: WFR): Engages in the development, manufacture, and sale of silicon wafers for the semiconductor industry worldwide. Over the last six months, insiders were net buyers of 355,195 shares, which represents about 0.15% of the company's 229.96M share float.

Interactive Chart: Press Play to compare changes in analyst ratings over the last two years for the stocks mentioned above. Analyst ratings sourced from Zacks Investment Research.


Kapitall's Alexander Crawford does not own any of the shares mentioned above. Short data sourced from Yahoo! Finance, all other data sourced from Finviz.