Schedule 13D vs 13G: Rules and Deadlines

Schedule 13D vs Schedule 13G is the fork a shareholder reaches the moment a stake in a US-listed company crosses 5% of a class of registered voting stock. Cross that line while holding open the option of influencing control, and the filing owed is a Schedule 13D. Cross it as a passive holder or as a qualifying institution, and the filing is the far shorter Schedule 13G. Both deadlines were cut by SEC amendments adopted in October 2023, and a great many explainers online still quote the retired ten-day clock.

Who has to file at 5%, and which schedule?

Section 13(d) of the Securities Exchange Act attaches to beneficial ownership rather than to shares parked in an account. A person beneficially owns a security if they hold voting power over it, investment power over it, or the right to acquire either within 60 days. Investors acting together are counted as one group against the same 5% line. Once the position crosses, the clock starts.

Which schedule applies turns on who the filer is and on what the filer might do.

• Schedule 13D is the default. It is owed by anyone above 5% who may seek to influence or change control of the issuer.
• Schedule 13G is the short form for passive investors, who stay under 20% and disclaim any control purpose.
• Qualified institutional investors, meaning registered advisers, banks, insurers and broker-dealers buying in the ordinary course of business, may also use 13G.
• Exempt investors, above 5% without a qualifying acquisition, file 13G as well.

The 13D side of that fork is event driven: a filing follows a crossing rather than a calendar date. The panel below counts the 13D family, initial filings and amendments together, month by month over the past two years.

SELECT
    toString(toStartOfMonth(filing_date))                AS month,
    formatDateTime(toStartOfMonth(filing_date), '%b %Y') AS month_label,
    count()                                              AS filings_13d
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= toStartOfMonth(today() - 730)
  AND filing_date <  toStartOfMonth(today())
  AND form_type LIKE 'SC 13D%'
GROUP BY toStartOfMonth(filing_date)
ORDER BY month

In Jul 2026, the most recent complete month in view, the index carried 4 filings in the 13D family, one of 16 months with 13D activity in the two-year window. Schedule 13G runs on its own calendar: most 13G obligations now land on the 45th day after a calendar quarter closes, which puts the bulk of them in mid-February, mid-May, mid-August and mid-November.

Schedule 13D vs 13G deadlines after the 2023 amendments

The SEC adopted the amended beneficial ownership rules on October 10, 2023, and the shortened windows took effect on February 5, 2024. The ten-calendar-day 13D deadline that older articles still cite no longer exists. The current clocks:

• Schedule 13D, initial filing: five business days after crossing 5%, down from ten calendar days.
• Schedule 13D, amendment: two business days after a material change in what was disclosed. The old standard was the single word promptly.
• Schedule 13G, passive investor: five business days after crossing 5%, then two business days after passing 10% or moving 5 percentage points above it.
• Schedule 13G, qualified institutional investor: 45 days after the end of the calendar quarter in which the stake passed 5%, then five business days after the end of a month in which it passed 10%.
• Schedule 13G amendments, all filers: 45 days after the end of any calendar quarter in which the reported facts changed materially. That replaced a once-a-year amendment.

Each of those windows has an amendment counterpart, and a position that keeps moving keeps generating filings under the same schedule.

What is in Item 4, Purpose of Transaction?

Item 4 is the part of a 13D that experienced readers open first. It asks the filer to state the purpose of the acquisition and to disclose any plan or proposal relating to a defined list of corporate actions:

• buying more stock, or selling the position down
• an extraordinary transaction such as a merger, a reorganization or a liquidation
• a sale or transfer of a material amount of the company's assets
• a change in the board or in management, including board size and unfilled seats
• a material change in capitalization or in dividend policy
• changes to the charter or bylaws, including anything that would impede an acquisition of control
• delisting the stock or deregistering the class

Most Item 4 text is written broadly, reserving the right to talk with management or with other holders. Read it as a floor rather than a plan. A Schedule 13G has no Item 4 at all, and a holder with a control plan has no honest way to file one.

Why a 13G to 13D switch matters more than a first filing

A fresh 13D from a fund nobody follows is routine. The move worth watching is a holder that has filed 13Gs on a name for years turning up with a 13D on that same name. The switch is a signed statement that the purpose has changed.

Two mechanics give it weight. The filer has five business days from the change of intent, which puts the disclosure close to the decision. A cooling off provision also applies: from the moment the purpose changes until the tenth day after the 13D is filed, that holder may not vote the shares and may not add to the position.

The panel below finds companies that already had 13G filings on record and then drew an initial 13D, most recent first.

WITH latest_13d AS
(
    SELECT
        ticker,
        any(issuer_name) AS issuer_name,
        max(filing_date) AS d_date
    FROM global_markets.stocks_sec_edgar_index
    WHERE form_type = 'SC 13D'
      AND filing_date >= today() - 1095
      AND ticker != ''
      AND ticker NOT IN ('SPCX')
    GROUP BY ticker
)
SELECT
    d.ticker                                        AS ticker,
    d.issuer_name                                   AS issuer,
    formatDateTime(max(g.filing_date), '%b %e, %Y') AS prior_13g,
    formatDateTime(d.d_date, '%b %e, %Y')           AS filed_13d,
    dateDiff('day', max(g.filing_date), d.d_date)   AS days_between
FROM latest_13d AS d
INNER JOIN
(
    SELECT ticker, filing_date
    FROM global_markets.stocks_sec_edgar_index
    WHERE form_type LIKE 'SC 13G%'
      AND filing_date >= today() - 1460
      AND ticker != ''
      AND ticker NOT IN ('SPCX')
) AS g ON g.ticker = d.ticker
WHERE g.filing_date < d.d_date
GROUP BY d.ticker, d.issuer_name, d.d_date
ORDER BY d.d_date DESC, d.ticker
LIMIT 12

The latest case in view is Neuronetics, Inc., where an initial 13D was filed on Dec 17, 2024, 33 days after the last 13G on the same company. One caution on reading it: the filing index keys on the subject company, not on the filer. A row here means a 13D arrived at a company with 13G holders already on file. Confirming that one holder made the switch means opening both filings and comparing the filer names.

Which companies draw the most 13D filings?

SELECT
    ticker,
    any(issuer_name)                AS issuer,
    countIf(form_type = 'SC 13D')   AS initial_13d,
    countIf(form_type = 'SC 13D/A') AS amendments
FROM global_markets.stocks_sec_edgar_index
WHERE form_type LIKE 'SC 13D%'
  AND filing_date >= today() - 548
  AND filing_date <  today()
  AND ticker != ''
  AND ticker NOT IN ('SPCX')
GROUP BY ticker
ORDER BY (initial_13d + amendments) DESC, ticker
LIMIT 12

GENCO SHIPPING & TRADING LTD sits at the top of the last 18 months with 0 initial 13D filings and 22 amendments. A stack of amendments on one name points to a stake that keeps changing size, with each move past a reporting line pulling a fresh filing inside two business days.

How 13D and 13G differ from Form 4 and 13F

Three ownership regimes overlap, and readers mix them up constantly. Section 13(d) covers outside holders above 5%, on the two schedules here. Section 16 covers insiders: officers, directors and 10% owners, whose individual trades post on a Form 4 within two business days. Our guide to how to read a Form 4 walks through the transaction codes. Section 13(f) covers institutional managers holding at least $100 million in qualifying US equities, whose whole long book posts once a quarter, 45 days after it ends; when 13F filings are due covers the lag that creates. For the wider map of company and investor filings, see the most common SEC filings.

Why a filer's percentage can outrun their share count

Beneficial ownership reaches past shares held outright. Anything exercisable or convertible within 60 days counts too: call options, warrants, convertible notes, units vesting inside the window.

The denominator moves with it. Shares a person has the right to acquire within 60 days are treated as outstanding when computing that person's percentage, and are not counted as outstanding for anyone else's. Take a hypothetical company with 100 million shares out. A holder of 4 million shares plus options on 3 million more reports 7 million of 103 million, which is 6.8%, not 4%. That arithmetic is why a reported percentage can sit oddly next to the share line beside it, and why two filers' percentages need not add up the way a plain stock float calculation suggests.

FAQ

What is the difference between Schedule 13D and Schedule 13G?

Both are filed by holders of more than 5% of a company's registered voting stock. Schedule 13D is the long form for anyone who may seek to influence or change control, and it carries Item 4, a written statement of purpose. Schedule 13G is a short form open to passive holders and to qualifying institutions, with no purpose section.

How long do you have to file a Schedule 13D?

Five business days after crossing 5%, and two business days for each later amendment. Those windows replaced the ten calendar day initial deadline and the older promptly standard on February 5, 2024.

What happens when a 13G filer switches to a 13D?

The holder files a Schedule 13D within five business days of the change in purpose and completes Item 4. From the change of intent until ten days after that filing, the holder may not vote the shares or buy more.

Do stock options count toward the 5% reporting threshold?

Yes, when they are exercisable within 60 days. Warrants and convertible securities work the same way. The underlying shares count toward the holder's stake and toward that holder's own denominator, which can lift a reported percentage well above what the outright share count implies.

Every panel here carries the SQL that produced it, expand one to see exactly which form codes were counted. To pull the 13D and 13G history on a company you follow, ask for it in plain English on the Strasmore terminal.