The Most Common SEC Filings, Explained by Data

The most common SEC filing is not the 10-K annual report, the 10-Q quarterly report, 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 every major form type in plain English, and shows why the documents investors actually read are a thin sliver of what the SEC receives.

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 101,000 every month, spread across 388 distinct form types from more than 154,000 separate 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
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()

Sort that year by form type and one category runs away with it.

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 28.01% of every filing in the index, more than one in four. The next-largest single form, the 424B2 prospectus supplement, sits at 14.71%. From there the table steps down through 144, 8-K, NPORT-P, 3 and a long tail of the rest. The reports that anchor financial headlines — the 10-K and 10-Q — rank far down this list, which is 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 who owns more than 10% of a company — buys or sells that company's stock. The rule gives them about two business days after the trade to report it, and a large company has dozens of insiders trading throughout the year. Each transaction is its own filing, so the count climbs faster than any periodic report ever could. This is the raw feed behind every insider trading headline and every insider-buying tracker: each dot on those charts is one Form 4.

Two siblings round out the insider set. A Form 3 is the initial statement an insider files when they first take the role or cross the 10% line — a one-time baseline of what they already hold. A Form 5 is an annual clean-up for small transactions that were exempt from prompt Form 4 reporting. Form 3 alone ranks among the larger categories on the leaderboard above; the ongoing Form 4, filed trade after trade, dwarfs both.

Which SEC filings do investors actually read?

The filings that fill financial media — the annual and quarterly reports — are a fraction of the total volume. Here is the same trailing year for six forms nearly every investor has heard of.

SELECT form_type, count() AS filings
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
  AND form_type IN ('4', '8-K', '13F-HR', '10-Q', '10-K', 'S-1')
GROUP BY form_type
ORDER BY count() DESC

Form 4 posted 341150 filings over the year. The 8-K, a company's notice of a material event — an acquisition, an executive departure, a bankruptcy, an earnings release — came to 63515. The 13F-HR, the quarterly holdings report every institutional manager overseeing more than roughly $100 million must file, logged 32341; those snapshots arrive up to 45 days after a quarter closes, a disclosure lag in the same spirit as why published short interest is always about two weeks old. The documents retail investors study most closely trail all of them: the 10-Q quarterly report at 15951 and the 10-K annual report at just 6060. Rarest of the six is the S-1, most often the registration statement a company files to go public — 1101 of them, the paperwork behind a newly listed company's first weeks of trading.

What other SEC forms are filed most often?

Beyond the insider forms and the flagship reports, a handful of categories fill most of the rest of the leaderboard:

• 424B2 / 424B3 — prospectus supplements. When a company with securities already registered on a shelf actually sells a tranche, it files a 424B supplement with the final terms. Continuous debt and structured-note programs generate these in bulk, which puts the 424B family near the very top of the volume table.
• Form D — a private placement. A company raising money privately under Regulation D files a short Form D notice instead of registering the offering publicly. It marks capital raised outside the public markets entirely.
• Schedule 13D / 13G — crossing 5%. Anyone who acquires more than 5% of a public company's voting shares must disclose the stake. The 13D is the long form used by activist investors who may seek to influence the company; the 13G is the short form for passive holders such as index funds. The /A versions are amendments that update a position as it changes.
• NPORT-P — fund holdings. Registered funds — mutual funds and ETFs — report their portfolios to the SEC on Form NPORT-P, which is why fund paperwork alone makes up a meaningful chunk of the index.
• Form 144 — selling restricted stock. An insider or affiliate who plans to sell restricted or control shares files a Form 144 notice first. It describes a proposed sale, not a completed one.
• 6-K — foreign issuers. A company based outside the U.S. that lists here reports material news on Form 6-K rather than the 8-K and 10-Q that domestic issuers use.

The through-line: EDGAR is far larger than the few thousand names a stock-picker follows. Only 46.5% of the past year's filings even carry a stock ticker — the field is frequently left blank even for insider (Form 4) and corporate filings about public, tickered companies, and much of the remainder genuinely comes from funds, private companies, and advisers with no single public symbol.

Do SEC filings arrive every day?

EDGAR runs on the business calendar. The index carries filing dates on 5 days of the week and none on the other two — no filing date lands on a Saturday or Sunday. The load spreads fairly evenly across the business week, from 224995 filings dated Monday to 257992 on Tuesday, with a mild midweek bulge.

SELECT ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'][toDayOfWeek(filing_date)] AS weekday,
       count() AS filings
FROM global_markets.stocks_sec_edgar_index
WHERE filing_date >= today() - INTERVAL 12 MONTH AND filing_date < today()
GROUP BY toDayOfWeek(filing_date), weekday
ORDER BY toDayOfWeek(filing_date)

Filing dates in this index are calendar days with no time attached, so the panel measures the date a filing is stamped, not the hour it hits the wire. The same index has its own completeness quirks — see the near-empty month-end days documented in a note on an EDGAR index gap, which clip a few boundary days without moving the year's shares.

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 28.01% of every filing in the EDGAR index — far ahead of any annual or quarterly report.

Is the 10-K the most common SEC filing?

No. The 10-K annual report is one of the best-known filings but one of the less frequent — a public company files it once a year. The index carried 6060 of them over the trailing year, against 341150 insider Form 4s.

What is the difference between a 10-K and a 10-Q?

The 10-K is the comprehensive annual report, filed once a year with audited financial statements. The 10-Q is a lighter quarterly update, filed for the first three quarters of the year — the fourth quarter is folded into the annual 10-K. Over the trailing year the index shows 15951 10-Qs and 6060 10-Ks.

What is a Form 4, and why are there so many of them?

A Form 4 reports a change in a corporate insider's holdings — a purchase, sale, option exercise, or grant — and is due within about two business days of the transaction. A large company has many reporting insiders trading through the year, and each transaction is a separate filing, which is what carries Form 4 to the top of the volume table.

Are all SEC filings from public companies?

No — and even among the public ones, a stock ticker isn't always recorded. Only 46.5% of the past year's filings carry a ticker in the index; the field is often left blank even for insider (Form 4) and corporate filings about public, tickered companies. Much of the remainder genuinely comes from registered funds, private companies raising money under Regulation D, and investment advisers with no single public symbol.

Every panel above ships with the exact SQL that generated it — open any panel to audit the count yourself. To rank filings for any company, form type, or date range in plain English, ask the question on the Strasmore terminal.