Mark, fyi, insider trading can be both legal and illegal. I didn't say they were doing it
illegally, but most any companies officers who hold stock options do trade within their own company, and a lot if you look at their reports.
The legal version is when corporate insiders, officers, directors, employees and large shareholders, buy and sell stock in their own companies. Not illegal to do. If they are transparent to the public, when corporate or insiders trade in their own securities, they must report their trades to the SEC. Many stock investors and traders then use that information to identify companies with investment potential, and the theory is if the insiders (CEO's, exec. board, etc.) are buying the stock, they must know more about their company than everyone else, so it is a good idea to buy the stock.
Where it gets messy and illegal is where they hide information from the SEC and public and provide tippees confidential information (ala, Martha Stewart.). Sometimes providing false information to sway public or financial institutions as well.
You can look up most any member on a companies board: CEO, Exec. etc. on the exchange and see how many shares they hold, sell, or buy. How they disclose it (To the SEC, public or not, or undercover and illegal.) is where it gets iffy. How they move it is where the market hopes to gain some info under a watchful eye.
No doubt a lot of 'questionable' trading goes on too and open to debate over legality. Cattle futures in Arkansas anyone?
SG