For our purposes, insiders are the company’s senior managers and directors, plus any shareholders who own at least 10% of the company’s stock. A company’s managers and directors have unique knowledge about the companies they run, so if they are purchasing its stock, it’s reasonable to assume that the company’s prospects look favorable.
Likewise, investors who own at least 10% of a company’s stock wouldn’t have bought so much if they didn’t see profit potential. Conversely, a sale of stock by an insider doesn’t necessarily point to bad news about the company’s anticipated performance — the insider might simply need cash for any number of personal reasons. Nonetheless, if mass sell-offs are occurring by insiders, such a situation may warrant further in-depth analysis of the reason behind the sale.