SEC Filing Types

A reference and decision guide for interpreting SEC forms in the context
of small-cap and quant research. Most quant code mishandles forms because
it treats "a filing exists" as the signal — the form TYPE and SPECIFIC
ITEM are the signal.

Core principle

A form's name tells you the company's PERMISSION to do something. The
specific item or supplement tells you whether they ACTED on it.

• An effective S-3 means a company can sell shares from the shelf.
  It does NOT mean they did.
• An S-3 plus a recent 424B5 plus a 10-Q reference to "at-the-market
  offering" means they ARE selling. That is the dilution signal.
• An 8-K is a sealed envelope until you read its specific items.
  Item 1.01 is benign or terrifying depending on the agreement.

Always inspect the SPECIFIC item / supplement / amendment, never the
form name alone.

Form reference (focused on small-cap dilution context)

Registration and offerings (the dilution machinery)

Form	What it means	Dilution implication
S-1 / S-1/A	IPO registration / amendment	New issuer; lockups in effect
S-3	Shelf registration (US issuer)	Permission, not action. Effective shelf = capacity to sell
S-3ASR	Automatic shelf (large issuers)	Same as S-3 but no SEC review delay
S-8	Employee plan registration	Adds shares to float as RSUs/options vest
F-1 / F-3	Foreign issuer equivalents of S-1 / S-3	Same logic, FPI
424B1–424B7	Prospectus supplement (actual takedown)	THIS is the action. Specifies shares offered, price, agents
FWP	Free writing prospectus	Marketing material, often pre-pricing of an offering

Material events

Form	Item	Meaning
8-K	1.01	Material definitive agreement (financing, partnership) — read the agreement
8-K	1.03	Bankruptcy / receivership — usually catastrophic
8-K	2.01	Completion of acquisition — share issuance possible
8-K	2.02	Earnings results
8-K	3.02	Unregistered equity sale (private placement / PIPE) — dilution happened
8-K	3.03	Modification of rights of holders
8-K	4.01 / 4.02	Auditor change / non-reliance on prior financials — red flag
8-K	5.02	Officer / director departure or appointment
8-K	5.07	Shareholder vote results
8-K	7.01	Reg FD disclosure (often offering announcement)
8-K	8.01	Other events — read the body

Periodic reports

Form	Cadence	Use for
10-K	Annual (US issuer)	Cover-page shares outstanding; full disclosures
10-K/A	Annual amendment	Supersedes the original from its own filing date forward
10-Q	Quarterly	Cover-page shares; subsequent-events note critical for offerings
20-F	Annual (FPI)	FPI equivalent of 10-K
6-K	Interim (FPI)	FPI equivalent of 10-Q + 8-K combined
NT 10-K / NT 10-Q	Late filing notice	Form 12b-25 — flag for compliance / Nasdaq listing risk

Ownership

Form	Filer	Trigger / use
SC 13D	Beneficial owner >5% (active intent)	Activist or controlling stake
SC 13G	Beneficial owner >5% (passive)	Institutional (Vanguard, BlackRock)
SC 13D/A, SC 13G/A	Amendments	Material change in holdings or intent
13F	Institutional manager ($100M+)	Quarterly, 45-day lag — never realtime
Form 3	Initial insider statement	First-time officer / director / 10% holder
Form 4	Insider transaction	Buys, sells, option exercises — usually within 2 business days
Form 5	Annual catch-up insider	Transactions exempt from Form 4
Form 144	Notice of intent to sell restricted shares	Affiliate signaling intent (not always executed)

Governance & misc

Form	Use
DEF 14A	Proxy statement; record-date share count, exec comp
PRE 14A	Preliminary proxy
DEFA14A	Additional proxy materials
CORRESP, UPLOAD	SEC correspondence (letters, comment-letter responses)

Decision rules small-cap-relevant

1. "Is this company actively diluting?"
   Need (a) effective S-3/F-3 + (b) 424B in the last ~30 days OR
   8-K item 3.02 + (c) low cash runway in last 10-Q. All three together
   = active dilution. Just an S-3 = capacity only.

2. "Is the offering toxic structure?"
   Look at the 424B for: warrants attached, pricing at discount to
   market, placement agent identity (see bank-tier-classification),
   ELOC / equity line language, "best efforts" vs "firm commitment".

3. "Should I trust the latest 10-K numbers?"
   Check for any 10-K/A filed AFTER the 10-K. The amendment supersedes
   from its own filing_date forward (see lookahead-safety).

4. "Does this 8-K matter?"
   Items 1.01, 1.03, 3.02, 4.01, 4.02, 5.02 require reading the body.
   Item 2.02 (earnings) is routine. Item 7.01 is often a heads-up of
   a pending offering — pair with same-day or next-day 424B watch.

5. "Is this insider buying or selling?"
   Form 4 transaction codes: P (open-market purchase) and S (open-market
   sale) matter most. A (grant), M (option exercise), F (tax withhold)
   are noise for sentiment.

6. "Late filing — should I care?"
   NT 10-K / NT 10-Q triggers a 15-day extension (5 for 10-Q). Failure
   to file by the extension creates Nasdaq compliance risk and is a
   short-side signal for very small companies.

Common confusions

• S-1 vs S-3. S-1 is for new issuers / first registrations. S-3 is
  for established issuers raising via a shelf. Confusing these mis-frames
  the company's stage.
• "Effective" vs "filed". S-3 has both: SEC declares effective some
  weeks after filing. Until effective, no takedown is possible.
• 424B variants. B1–B7 differ in WHAT is being supplemented. B5 is
  the most common for small-cap shelf takedowns; B2 for IPO-related;
  B4 for FPIs. The variant matters for parsing but all are takedowns.
• 13D vs 13G. Same threshold (>5%), different intent. 13D = active,
  13G = passive. A 13G → 13D conversion is a strong signal.
• 6-K is not 8-K. FPIs have no 8-K; material events flow through 6-K.
  Don't filter for "8-K" on FPIs — you'll miss everything.
• Form 144 ≠ Form 4. 144 is intent to sell restricted shares; the
  actual sale (if it happens) appears later as a Form 4. Treating 144
  as an executed sale is a common quant bug.

Workflow when analyzing a filing list

1. Bucket filings by category (registration, periodic, event, ownership).
2. For 8-Ks, immediately partition by item number — don't treat them
   as a single bucket.
3. For each registration form, find the corresponding takedown
   (424B / 8-K item 3.02 / S-8 effective date) — registration without
   takedown is capacity, not action.
4. For amendments (10-K/A, S-3/A, etc.), apply lookahead-safety:
   the amendment is known only from ITS filing date.
5. For ownership filings, dedupe joint filers and treat 13F with the
   45-day lag explicitly.

Phrases that should trigger this skill

• "what does an 8-K item X mean"
• "is an S-3 a dilution event"
• "should I worry about this 424B"
• "13D vs 13G"
• "explain this filing"
• any specific form name: S-1, S-3, 424B5, 8-K, 10-K, 20-F, 6-K, 13D, 13G, 13F, Form 4, NT 10-K, DEF 14A
• "EDGAR" + analysis
• "is this company diluting"

What this skill is NOT

This is not a parser or extractor. It does not pull values from filings.
It tells you what each form / item / amendment MEANS so the LLM can
reason correctly about the data once it's pulled. Combine with
lookahead-safety for time semantics, and (when available)
atm-detection and bank-tier-classification for dilution-specific
inference.