When is a Schedule 13D due?

Within five business days after crossing 5%, with amendments within two business days of a material change (the deadlines since 2024).

What's the difference between a 13D and a 13G?

A 13D is for holders who may seek to influence the company; a 13G is a shorter form for passive holders.

Does a 13D mean the investor will push for changes?

Not always. Read the purpose section: many 13Ds state only an investment purpose.

Learn · SEC filings

What is a Schedule 13D?

A Schedule 13D is the filing an investor makes after acquiring more than 5% of a class of a public company's voting shares, when that investor may want to influence or change the company. It's often called the "activist" filing. Since 2024, the first 13D is due within five business days of crossing 5%, and amendments are due within two business days of a material change, such as buying or selling a meaningful amount or changing plans.

What a 13D shows

Who is filing, including any group of investors acting together
The stake: number of shares and percentage of the class
Item 4, Purpose of the transaction: often the most-read part. It can be generic ("investment purposes") or specific: seeking board seats, pushing for a sale, opposing a deal, or a settlement with the company.
Source of the money and any agreements with the company or other holders

13D vs 13G

Investors who cross 5% but are passive, with no intent to influence control, can usually file the shorter Schedule 13G instead. Under the 2024 rules, passive investors file a 13G within five business days of crossing 5%. Many institutional investors file within 45 days after the quarter's end. A switch from 13G to 13D can matter, because it signals the holder may become active.

How AlphaFilings uses 13Ds

We read every new 13D and amendment, keep the stake and the stated purpose, and flag board events: seats won, nominations, agreements and settlements. Stakes taken as part of a takeover or control deal are labelled separately from activist positions.

See recent activist stakes →

Questions

When is a Schedule 13D due?: Within five business days after crossing 5%, with amendments within two business days of a material change (the deadlines since 2024).
What's the difference between a 13D and a 13G?: A 13D is for holders who may seek to influence the company; a 13G is a shorter form for passive holders.
Does a 13D mean the investor will push for changes?: Not always. Read the purpose section: many 13Ds state only an investment purpose.

Updated 2026-11-02. Rules and deadlines are summarised from the SEC's own guidance; check the SEC's pages for the full requirements. This page is general education, not investment advice.