Schedule 13D and 13G
Filings required when an investor passes 5 percent ownership of a public company, with 13D for active intent and 13G for passive holders.
Schedules 13D and 13G are beneficial ownership reports filed with the SEC when a person or group acquires more than 5 percent of a company's voting shares. A 13D is used by holders who intend to influence control or management, such as activists, and it requires fuller disclosure of plans. A 13G is available to passive holders and certain institutions, with simpler disclosure.
On our site, these filings are labeled 13D or 13G with the filer and the percentage held. A 13D often includes the investor's letter and plans in its item sections.
Traders care because a 13D from an activist can signal a campaign that changes a company's strategy, and the stock often moves on the filing.
Worked example (illustrative numbers, not real data): a fund discloses that it holds 6 percent of a company's 100 million shares, or 6 million shares, and files a 13D saying it wants to replace two directors. The filing signals possible activism, not a guaranteed campaign.