The Most Common SEC Filings, Explained by Data

The most common SEC filing is not the 10-K annual report, the 10-Q, or the 8-K that scrolls across the screen on earnings day. It is the humble Form 4, the one-page insider-transaction notice a company officer, director or large shareholder files after buying or selling stock. This page ranks the most common SEC filings straight from the EDGAR index, defines each major form in plain English, and ends with the practical part: how to pull up a company's filings and read one.

What are the most common SEC filings?

EDGAR, the SEC's Electronic Data Gathering, Analysis, and Retrieval system, is the public database every U.S. securities filing lands in. Our copy of its daily index took in more than 1.2 million filings over the trailing year, roughly 104,000 a month, across 387 form types from more than 156,000 filers.

SELECT floor(count() / 1e5) / 10 AS filings_millions,
       round(count() / 12 / 1000) AS avg_per_month_k,
       uniqExact(form_type) AS distinct_form_types,
       floor(uniqExact(cik) / 1000) AS distinct_filers_k,
       round(100.0 * countIf(ticker != '') / count(), 1) AS pct_with_ticker,
       round(100.0 * countIf(endsWith(form_type, '/A')) / count(), 1) AS pct_amendments,
       round(100.0 * countIf(form_type = '4/A') / countIf(form_type IN ('4', '4/A')), 1) AS pct_form4_amended
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()

Sort it by form type and one category runs away with the rest.

SELECT form_type,
       round(100.0 * count() / (SELECT count() FROM global_markets.stocks_sec_edgar_index WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()), 2) AS pct_of_filings
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
GROUP BY form_type
ORDER BY count() DESC
LIMIT 12

Form 4, the insider-transaction report, accounts for 27.9% of every filing in the index, more than one in four. The next-largest single form, the 424B2 prospectus supplement, sits at 14.94%; from there the table steps down through 144, 8-K, NPORT-P, 3 and a long tail. The reports that anchor financial headlines, the 10-K and 10-Q, rank far down this list, the first surprise the data hands you.

Why is Form 4 the most common SEC filing?

A Form 4 is filed whenever a corporate insider, an officer, a director, or a shareholder owning more than 10% of a company, buys or sells that company's stock. The rule allows about two business days after the trade, and a large company has dozens of insiders trading through the year. Each transaction is its own filing, so the count climbs faster than any periodic report can. This is the raw feed behind every insider trading headline.

Two siblings round out the insider set. A Form 3 is the initial statement an insider files on taking the role or crossing the 10% line. A Form 5 is an annual clean-up for small transactions exempt from prompt Form 4 reporting. Form 3 ranks among the larger categories on the leaderboard above; the ongoing Form 4 dwarfs both.

Which SEC filings do investors actually read?

The filings that fill financial media are a fraction of total volume. Here are eight forms every investor has heard of, each with its rank among all 387 form types.

SELECT form_type, filings, overall_rank, filings_display
FROM (
    SELECT form_type,
           count() AS filings,
           reverse(arrayStringConcat(extractAll(reverse(toString(count())), '[0-9]{1,3}'), ',')) AS filings_display,
           row_number() OVER (ORDER BY count() DESC, form_type) AS overall_rank
    FROM global_markets.stocks_sec_edgar_index
    WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
    GROUP BY form_type
)
WHERE form_type IN ('4', '8-K', '13F-HR', '10-Q', 'DEFA14A', '10-K', 'DEF 14A', 'S-1')
ORDER BY filings DESC

Form 4 posted 347,404 filings, rank 1. The 8-K, a notice of a material event (an acquisition, an executive departure, a bankruptcy, an earnings release), came to 63,670 at rank 4. The 13F-HR, the quarterly holdings report every manager running more than roughly $100 million must file, logged 34,240, snapshots that arrive up to 45 days after a quarter closes, a disclosure lag in the spirit of why published short interest is always about two weeks old. The documents retail investors study most closely trail all of them: the 10-Q at 16,566, the 10-K at just 6,055, rank 26 of 387. Rarest of the eight is the S-1, usually the registration statement for going public: 1,091, the paperwork behind a newly listed company's first weeks of trading.

Where does the DEF 14A proxy statement fit?

The DEF 14A, the definitive proxy statement, is the annual-meeting booklet: the ballot for directors and the auditor, the say-on-pay vote, and the executive-compensation tables behind every "CEO earned X times the median employee" headline. One of the most-read documents a company publishes, yet the index carried only 4,954 over the trailing year, at rank 30. The arithmetic matches the 10-K's: one a year per operating company.

Its noisier relative sits alongside it. DEFA14A, "additional soliciting material", covers anything else sent to shareholders about that vote: decks, letters urging a yes, proxy-advisor rebuttals. A contested vote generates a stream of them, and the index shows 6,621 DEFA14As against 4,954 DEF 14As. Two relatives complete the family: PRE 14A, the preliminary version filed for SEC staff review, and DFAN14A, the same material filed by an activist running a rival slate.

What other SEC forms are filed most often?

Four categories fill most of the rest of the leaderboard:

• 424B2 / 424B3, prospectus supplements. A shelf-registered issuer files one with the final terms each time it sells a tranche; debt and structured-note programs generate them in bulk.
• Form 144, selling restricted stock. An insider's notice of a proposed sale of restricted or control shares, not a completed one.
• Schedule 13D / 13G, crossing 5%. The 13D is the long form used by activists; the 13G is the short form for passive holders such as index funds.
• NPORT-P, Form D, 6-K. Fund portfolios; private Regulation D raises; a foreign issuer's news.

EDGAR is far larger than the few thousand names a stock-picker follows. Only 46.4% of the past year's filings even carry a ticker, the field is often blank even for filings about public companies, and much of the rest comes from funds, private companies and advisers with no public symbol.

What is an amended SEC filing (the /A forms)?

A form name ending in /A is an amendment, an update to a filing already on the record, not a new event. A 10-K/A restates an annual report; an 8-K/A adds statements a deal announcement promised later; a 4/A fixes a mis-keyed share count. They matter when counting filings: 7.7% of the index over the trailing year is an /A form.

SELECT form_type AS amended_form,
       count() AS amendments,
       reverse(arrayStringConcat(extractAll(reverse(toString(count())), '[0-9]{1,3}'), ',')) AS amendments_display,
       round(100.0 * count() / (SELECT countIf(endsWith(form_type, '/A')) FROM global_markets.stocks_sec_edgar_index WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()), 1) AS pct_of_amendments
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
  AND endsWith(form_type, '/A')
GROUP BY form_type
ORDER BY amendments DESC
LIMIT 8

This is not a table of mistakes. Its largest entry, SCHEDULE 13G/A, 33,916 filings, 35.5% of all amendments, is routine position maintenance: a passive 5%-plus holder updating a 13G as the stake moves. The runner-up, D/A at 21,990 filings and 23%, is the same for private placements. Genuine corrections are the smaller share: only 1.5% of insider Form 4s ever got a 4/A. Treat an /A as "here is the current version," and check its date before trusting a number from the original.

Are SEC filings increasing over time?

A 12-month snapshot says nothing about direction. Here are the last twelve full quarters: total filings, Form 4s, and Form 4's share of the whole.

SELECT formatDateTime(toStartOfQuarter(filing_date), '%Y-Q') || toString(toQuarter(filing_date)) AS quarter,
       round(count() / 1000.0, 1) AS all_filings_k,
       round(countIf(form_type = '4') / 1000.0, 1) AS form4_filings_k,
       reverse(arrayStringConcat(extractAll(reverse(toString(count())), '[0-9]{1,3}'), ',')) AS all_filings_display,
       reverse(arrayStringConcat(extractAll(reverse(toString(countIf(form_type = '4'))), '[0-9]{1,3}'), ',')) AS form4_filings_display,
       round(100.0 * countIf(form_type = '4') / count(), 1) AS form4_pct_of_filings
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= toStartOfQuarter(today() - INTERVAL 36 MONTH)
  AND filing_date < toStartOfQuarter(today())
GROUP BY quarter, toStartOfQuarter(filing_date)
ORDER BY toStartOfQuarter(filing_date)

Two readings. First, the mix is stable: Form 4 was 27.9% of all filings in 2023-Q3 and 29.9% in 2026-Q2, the newest full quarter, it wanders without climbing away from that band. Second, the wander is seasonal: the January-to-March quarters sit at the top of the range in every year the panel covers, the window when annual grants vest, proxies go out and 10-K season peaks. Total volume follows the same calendar, from 245,391 filings in 2023-Q3 to 336,460 in 2026-Q2, 100,769 of that last quarter Form 4s alone. An insider-activity screen is reading a seasonal series: a quiet August is a calendar artifact before it is a signal.

How to find a specific company's SEC filings

Every filer has a CIK, a Central Index Key, the permanent number the SEC identifies it by. Tickers change and get reused; a CIK never does, which is why the index keys on it. Apple's is 0000320193. Type a ticker or name into EDGAR's search at sec.gov/edgar/search to get the CIK, then browse that filer's history. One household name's year on EDGAR:

SELECT form_type,
       count() AS filings,
       any(cik) AS issuer_cik,
       max(filing_date) AS latest_filing,
       concat(monthName(max(filing_date)), ' ', toString(toDayOfMonth(max(filing_date))), ', ', toString(toYear(max(filing_date)))) AS latest_filing_readable,
       argMax(accession_number, (filing_date, accession_number)) AS latest_accession
FROM global_markets.stocks_sec_edgar_index
WHERE ticker = 'AAPL'
  AND filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
  AND form_type IN ('4', '144', '8-K', '10-Q', '10-K', 'DEF 14A')
GROUP BY form_type
ORDER BY multiIf(form_type = '4', 1, form_type = '144', 2, form_type = '8-K', 3, form_type = '10-Q', 4, form_type = '10-K', 5, 6)

The cadence of a large operating company shows up cleanly: 1 10-K, 3 10-Qs and 1 DEF 14A proxy in the year, one per required period, against 42 Form 4s and 6 8-Ks, which arrive whenever an event does. Each row carries the accession number of the newest filing of that type: Apple's latest Form 4, filed August 20, 2026, is accession 0001140361-26-033928, the document's permanent address on EDGAR.

How to read a Form 4

Open one and you get a header (the insider's name and relationship, director, officer, 10% owner) and two tables: Table I for ordinary shares, Table II for derivatives. Each row is one transaction, and the column carrying the meaning is the single-letter transaction code.

• P, open-market purchase. The insider bought with their own money, the code insider-buying trackers care about.
• S, open-market sale. A cash sale, often pre-scheduled under a Rule 10b5-1 plan, which a footnote usually flags.
• A, award or grant. Shares handed over as compensation; no decision to buy is expressed.
• M, exercise of a derivative. Options or units converted into shares, often paired same-day with an F or an S.
• F, shares withheld for taxes. Looks like a sale in a raw feed; it is a withholding mechanic on a vesting grant.
• G, gift. A transfer with no cash consideration.

The rest of the row gives the share count, the price, and the holding afterwards, the last column says whether a headline sale was the whole position or a rounding error. Filter a feed to code P and the volume above shrinks to something a person can read. The index has quirks of its own, see a note on an EDGAR index gap.

FAQ

What is the most common SEC filing?

By volume it is the Form 4, the insider-transaction report an officer, director or 10%-plus owner files after trading company stock. Over the trailing year it made up 27.9% of every filing in the EDGAR index.

Is the 10-K the most common SEC filing?

No. It is one of the best-known filings but one of the less frequent, a public company files it once a year. The index carried 6,055 of them over the trailing year, against 347,404 insider Form 4s.

What is a DEF 14A proxy statement?

The booklet a company sends before its annual meeting: the director ballot, the auditor ratification, the say-on-pay vote and the executive-pay tables. One per operating company per year, the index shows 4,954 over the trailing year, rank 30 among all form types.

What does the transaction code on a Form 4 mean?

The single letter saying what happened: P open-market purchase, S sale, A compensation award, M option or unit exercise, F shares withheld for taxes on a vesting grant, G gift. Codes A, M and F are compensation mechanics, not decisions to buy or sell at that day's price.

Every panel above ships with the SQL that generated it, open one and audit the count. To rank filings for any company or form type in plain English, ask on the Strasmore terminal.