Definition
Schedule 13D is a beneficial-ownership disclosure filing required under §13(d) of the Exchange Act when a person (or group acting in concert) acquires more than 5% of a class of registered equity securities. The filing is due within 10 calendar days of crossing the threshold (the SEC adopted shorter deadlines in 2024 — verify current rules).
What’s in it
- Identity and background of the filer(s)
- Source and amount of funds for the purchase
- Purpose of the transaction (including any plans to seek control)
- Number and percentage of shares beneficially owned
- Contracts, arrangements, or understandings with respect to the security
Why it matters
Schedule 13D is the early-warning system for activist campaigns and creeping takeovers. The “purpose” disclosure is central — filers planning to pursue control or influence corporate strategy must say so. Material amendments are required when the filer’s position changes by 1% or more.
Distinction
Schedule 13G is the short-form alternative for passive investors (e.g., index funds) who do not intend to influence control. Switching from 13G to 13D is a known signal that a holder is becoming activist.