Schedule 13D vs 13G

The 5% rule

Section 13(d) of the Securities Exchange Act requires anyone who comes to own beneficially more than 5% of a class of a public company's voting equity to report it to the SEC. "Beneficially" means having the power to vote or sell the shares, so funds report on behalf of the people who run them, and groups acting together count as one.

Schedule 13D: the activist form

A 13D is the long form. It names who's behind the stake, how big it is, where the money came from, and, in Item 4, the purpose: whether they plan to seek board seats, push for a sale or a split, change the capital structure, or just hold. Item 4 is the part to read; "investment purposes" with a long list of reserved rights is boilerplate, while a named plan or a letter to the board is news.

Since the SEC's 2023 amendments, an initial 13D is due within 5 business days of crossing 5% (it was 10 calendar days), and a material change, such as buying or selling 1% or more, needs an amendment within 2 business days.

Schedule 13G: the passive form

A 13G is a much shorter filing for investors who certify they have no intention of influencing control. There are three kinds:

• Qualified institutional investors (banks, brokers, insurers, registered funds and advisers) file within 45 days after the end of the quarter in which they crossed 5%, sooner if they pass 10%.
• Exempt investors (for example, holders since before the company went public) follow similar quarterly timing.
• Passive investors holding under 20% file within 5 business days.

Most 13G filings, and most 13G amendments, come from the biggest index fund managers adjusting routine positions. They rarely say anything new about a company.

When a 13G becomes a 13D

A passive holder that decides to get involved must switch to a 13D, and can't vote the shares or buy more until shortly after it's filed. A switch from 13G to 13D is one of the more telling filings there is: a known holder has decided to act.

What to watch

• New 13Ds, especially from investors known for campaigns.
• 13D amendments that raise the stake or add a new Item 4 plan.
• Stakes falling below 5%: the holder is leaving.

Since December 2024 these filings are in structured data on EDGAR, which is how InsiderBeacon reads them within minutes. The app's Big stakes tab lists every new 13D and 13G with the holder's percentage, how it changed since their last filing and the 13D's stated purpose; you can get an alert on every new activist stake, or on any stake in a stock you follow. Every stock page lists its 5% holders.

Questions

For information only, from public SEC and congressional filings. Not investment advice. Disclaimer