What is an Activist Investor?
Every investor that acquires 5% of a company is required to file a beneficial ownership filing, which is either a Form 13D or Form 13G, within ten (10) days of the event. If the investor intends to influence management, then they are considered an activist investor and must file a 13D. Carl Icahn is a well-known activist investor. If they do not intend to influence management, then they are considered a passive investor and must file a 13G. Vanguard, because of it's size, owns more than 5% of many companies. Since it is a passively managed fund, it files Forms 13G. If there is any change in the ownership, investors must make amendments to their original filings, with either forms 13D/A, or 13G/A. If a passive investor that has filed a 13G decides they want to influence management, they must file a new 13D that supercedes their original 13G.
There is evidence that suggests investing alongside activist investors is a stock market investing strategy that can produce excess returns. This free screener shows all of the required Schedule 13D filings made by activist investors.
Additionally, filers of 13Ds often organize investor groups in order to have more leverage when influencing management. Fintel only identifies the lead investor of an investor group. To see the other members of the group, read the original filing by clicking on the form type in the Form column. You cannot directly compare shares reported in a 13D/G with shares reported by the investor in a 13F, since the 13D/G filings may include other investors.
Change in holdings is calculated as (current - previous) / previous.