SEC Filing Cheat Sheet

SEC filings are easier to trade around when you know what each form is trying to accomplish. A filing label alone is not enough. An S-1 can be an IPO, a discounted follow-on, or a resale registration. A 424B5 can be an ATM supplement or the final prospectus for a shelf takedown. A 13D can signal activist pressure, while a 13G is usually passive ownership.

This guide is built for the practical read: why the filing appears, when it normally shows up, how to tell similar filings apart, and whether it tends to matter immediately for price. The impact labels are trading shorthand, not legal advice. Always verify the actual filing, exhibits, selling holder tables, share counts, and subsequent events before treating a form type as bullish or bearish.

Current as of June 11, 2026. Timing notes use SEC rules and SEC staff materials where possible. In particular, the Schedule 13D and 13G timing below reflects the SEC's modernized beneficial ownership rules, not the older 10-day and annual amendment deadlines many older cheat sheets still show.

Interactive filing guide

Search by form, catalyst, deadline, or trading read. Impact labels describe common immediate market reaction, not legal importance.

Showing 38 of 38Updated Jun 2026

Category	Filing	Why it appears	Timing	How to spot it	Impact	Trader read	Example
Dilution	S-1 / F-1	IPO registration	Usually filed months before an IPO prices.	The cover page and prospectus summary describe an initial public offering.	None	The filing starts the IPO disclosure process. It usually does not create immediate secondary-market supply for an already public stock.	SEC example
Dilution	S-1 / F-1	Follow-on or secondary offering	Often filed shortly before pricing if the issuer is not using an effective shelf.	Look for a maximum dollar amount, placeholders for share count and price, and an underwriter or placement agent.	Medium	This can signal a discounted raise is coming. The first filing matters most when there was no earlier press release or obvious financing setup.	SEC example
Dilution	S-1 / F-1	Resale registration	Common after a PIPE, warrant issuance, convertible deal, or equity line agreement.	The selling stockholder table identifies who can resell, how many shares, and the source of those shares.	Low	The first filing does not usually unlock shares by itself. Watch for effectiveness and compare the registered share count with the float.	SEC example
Dilution	S-1/A / F-1/A	Amendment to an earlier S-1 or F-1	Filed between the first registration statement and effectiveness.	The SEC file number links it back to the original registration statement.	None	Amendments usually clean up disclosure, add exhibits, update financials, or fill in deal terms. Price impact comes from new economics, not the amendment label.	SEC example
Dilution	EFFECT	SEC notice that a registration statement is effective	After SEC review or automatically for certain shelves.	Use the file number to see which S-1, F-1, S-3, F-3, or F-10 became effective.	Medium	For small-cap offerings, effectiveness can mean pricing is close. For resale registrations, it can mean restricted shares are closer to being freely tradable.	SEC example
Dilution	S-1MEF / F-1MEF	Registration of additional offering securities	After effectiveness and near pricing.	The filing references the prior registration statement and Rule 462(b).	Medium	A MEF filing can indicate the deal is moving and may be larger than the base registration covered.	SEC example
Dilution	424B4	Final IPO or S-1/F-1 offering prospectus	After pricing.	It contains the final share count, public offering price, underwriting discount, and use of proceeds.	None	By the time this appears, the pricing press release usually already told the market the important economics.	SEC example
Dilution	S-3 / F-3 / F-10	Shelf registration	Filed when an eligible issuer wants capacity to sell securities over time.	The prospectus lists the security types and a maximum aggregate amount unless it is an automatic shelf.	Low	An uneffective shelf is capacity, not an immediate sale. After effectiveness, the issuer can tap it with a supplement.	SEC example
Dilution	S-3 / F-3	Resale shelf	Common after private financings or equity-linked deals.	The selling securityholder section is the key table.	Low	The market impact depends on float size, lockups, holder incentives, and whether the stock is already squeezed or supply-constrained.	SEC example
Dilution	S-3ASR / F-3ASR	Automatic shelf for a well-known seasoned issuer	Available to WKSIs and effective immediately when filed.	The dollar amount may be blank, and the form type includes ASR.	Low	Immediate effectiveness makes it more actionable than an ordinary shelf, but large issuers often file ASRs as routine financing infrastructure.	SEC example
Dilution	S-3MEF / F-3MEF	Additional securities for a shelf takedown	Near an offering or shortly after a shelf is used.	The filing references a prior effective shelf and registers additional securities.	Medium	It is more relevant when the company is actively raising or the market is waiting for supply.	SEC example
Dilution	424B5	At-the-market offering supplement	After the related shelf is effective.	Search for at-the-market offering, equity distribution agreement, sales agreement, or from time to time.	Medium	An ATM does not prove immediate selling, but it gives the issuer a live path to sell into volume. It matters more after big runs or with short runway.	SEC example
Dilution	424B5	Final shelf takedown prospectus	Around or after pricing of an offering off a shelf.	The supplement states the actual shares, warrants, units, price, and gross proceeds.	None	Usually confirms deal terms that the company already announced.	SEC example
Dilution	424B3	Resale prospectus after effectiveness	After the resale registration statement becomes effective or needs updating.	It generally tracks the earlier resale registration statement and selling holder table.	Low	This is a stronger unlock signal than the first S-1 filing, especially when registered shares dwarf the public float.	SEC example
Dilution	RW	Withdrawal of a registration statement	After a company decides not to pursue the registration.	The letter asks the SEC to withdraw a specific registration statement by file number.	Medium	Can remove a financing overhang if traders expected a near-term offering. Resale withdrawals usually matter less.	SEC example
Financials	10-Q	Quarterly report for domestic issuers	40 days after quarter-end for accelerated and large accelerated filers, 45 days for others.	Contains quarterly financial statements, MD&A, risk updates, and share count disclosures.	Low	Often follows earnings. For dilution work, inspect cash, burn, shares outstanding, subsequent events, and financing footnotes.	SEC example
Financials	10-K	Annual report for domestic issuers	60, 75, or 90 days after fiscal year-end depending on filer status.	Contains audited annual financial statements, MD&A, risk factors, and full-year disclosures.	Low	For small caps, this is often the best baseline for cash runway, share count history, warrants, converts, and going-concern language.	SEC example
Financials	20-F	Annual report for foreign private issuers	Due within four months after fiscal year-end.	Foreign private issuer annual report with audited financials and company disclosure.	Low	Treat it like the foreign issuer version of a 10-K. Quarterly updates may arrive through 6-Ks instead of 10-Qs.	SEC example
Financials	40-F	Annual report for certain Canadian issuers	Filed by eligible Canadian issuers using the multijurisdictional disclosure system.	Often incorporates Canadian annual information form and audited financial statements.	None	Useful for financials and share data, but usually not an immediate catalyst by itself.	SEC example
Material Events	8-K	Current report for material events	Generally within four business days after a triggering event.	Read the item numbers and exhibits. The exhibit often has the contract, press release, or financing agreement.	High	8-Ks can move stocks when they reveal financings, delistings, restructurings, M&A, earnings, auditor changes, or bankruptcy risk before the market has digested them.	SEC example
Material Events	6-K	Foreign issuer current report	Furnished promptly after material information is made public abroad or distributed to shareholders.	Look at the attached exhibit, press release, financial update, or transaction document.	High	For foreign small caps, 6-Ks can carry offering terms, compliance notices, financials, and business updates that a domestic issuer might report on 8-K.	SEC example
Ownership	Schedule 13D	Activist or control-oriented holder above 5%	Current SEC rules generally require the initial filing within five business days after crossing 5%.	Item 4 explains the purpose of the transaction. Item 5 shows ownership and recent transactions.	Medium	Can be bullish if a credible activist builds a large stake, but the actual plan and financing arrangements matter.	SEC example
Ownership	Schedule 13G	Passive or exempt holder above 5%	Deadlines vary by filer type. Passive investors generally file within five business days; QIIs and exempt investors use quarter-end based timing.	The cover page identifies filer type and the table shows beneficial ownership percentage.	Medium	Usually less aggressive than a 13D, but still relevant when a respected investor owns a large part of the float.	SEC example
Ownership	Schedule 13D/A	Amendment to activist ownership disclosure	Current SEC rules generally require amendments within two business days after a material change.	Compare current ownership and transaction tables with the prior amendment.	Low	The signal depends on whether the holder bought, sold, changed intent, nominated directors, or entered a standstill.	SEC example
Ownership	Schedule 13G/A	Amendment to passive ownership disclosure	All 13G filers generally amend within 45 days after quarter-end for material changes, with faster thresholds for some 10% and 5% changes.	Compare the new percentage and share count with the prior 13G.	Low	Often backward-looking, but useful for spotting large holder exits, float concentration, or ownership that changed during a move.	SEC example
Ownership	Form 3	Initial insider ownership report	Within 10 days after becoming an officer, director, or 10% holder.	Shows the insider's starting beneficial ownership.	None	It is a baseline filing. The useful signal comes from later Form 4 transactions.	SEC example
Ownership	Form 4	Insider transaction report	Generally within two business days after the transaction.	Transaction code, price, share amount, and footnotes explain what happened.	Medium	Open-market insider buys can matter. Option exercises, tax withholding, grants, and 10b5-1 sales usually need more context.	SEC example
Ownership	Form 5	Annual report of missed or deferred insider transactions	Within 45 days after fiscal year-end.	Lists transactions that were not required on Form 4 or were reported late.	None	Usually cleanup disclosure rather than a fresh trading signal.	SEC example
Proxies	PRE 14A	Preliminary proxy statement	At least 10 calendar days before definitive proxy materials are first sent unless an exception applies.	The document says preliminary and lists shareholder proposals.	Low	Small-cap traders care when proposals include reverse splits, authorized share increases, mergers, compensation plans, or recapitalizations.	SEC example
Proxies	DEF 14A	Definitive proxy statement	After any required preliminary review period or for the annual meeting.	Contains final proposals, voting instructions, ownership tables, compensation, and governance disclosures.	Low	For dilution work, inspect proposals for share authorization increases, equity plans, reverse splits, and financing-friendly charter changes.	SEC example
Proxies	DEFM14A	Definitive merger proxy	After a merger agreement when shareholder approval is needed.	The proxy focuses on merger terms, background, fairness opinions, and vote mechanics.	Low	Usually confirms known transaction details, but deal terms, financing, and vote risk can matter.	SEC example
Proxies	PREC14A / PRRN14A / DFAN14A	Proxy contest materials	When activists or other soliciting parties communicate competing proposals or nominees.	The filing comes from a soliciting shareholder or contains activist campaign materials.	Low	Can matter when the campaign pushes a sale, board change, capital return, financing block, or strategic review.	SEC example
Other	S-4 / F-4	Registration for securities issued in a merger or exchange offer	After a transaction announcement.	The document describes the transaction, parties, consideration, and registered securities.	Low	Most useful for understanding merger structure, exchange ratios, pro forma ownership, and closing conditions.	SEC example
Other	425	Additional merger or exchange-offer communication	After deal announcement and during solicitation.	Often contains investor decks, scripts, press releases, or deal communications.	Low	Usually overlaps with an 8-K exhibit but can add context around deal messaging or changed terms.	SEC example
Other	1-A	Regulation A offering statement	Before a Reg A offering is qualified.	The document has Part I and Part II offering circular sections rather than a traditional S-1 layout.	Low	Reg A issuers often differ from exchange-listed reporting companies. For traders, focus on offering size, qualification status, and post-offering share count.	SEC example
Other	1-U / 1-K / 1-SA	Reg A current, annual, and semiannual reports	1-U is event-driven; 1-K and 1-SA are periodic Reg A reports.	These are Reg A reporting forms, not ordinary 8-K, 10-K, or 10-Q reports.	None	Useful mainly when researching Reg A issuers or companies that recently moved into ordinary Exchange Act reporting.	SEC example
Other	13F-HR	Institutional investment manager holdings report	Within 45 days after quarter-end for managers with at least $100 million in reportable 13F securities.	The information table lists reported long positions.	Low	Backward-looking, but notable when a high-profile fund initiates, exits, or changes a stake that was not otherwise visible.	SEC example
Other	S-8	Employee benefit plan registration	Any time the company registers shares for equity plans.	The plan name and registered shares are usually on the cover page and exhibits.	None	S-8 shares can become saleable quickly, but they are tied to compensation plans and usually matter less than financing registrations.	SEC example

Dilution

S-1 / F-1

None

Why it appears: IPO registration
Timing: Usually filed months before an IPO prices.
How to spot it: The cover page and prospectus summary describe an initial public offering.
Trader read: The filing starts the IPO disclosure process. It usually does not create immediate secondary-market supply for an already public stock.

SEC Filing Cheat Sheet