13F Filing Thresholds: $100M, 5%, 13D vs 13G Decoder

The US securities reporting framework for institutional ownership uses multiple Forms with different filing thresholds. Reading institutional ownership correctly requires understanding which Form captures what, when, and at what threshold. Form 13F-HR requires institutional investment managers with $100+ million in US-listed equities to disclose their holdings quarterly. Schedule 13D requires any person or entity acquiring 5%+ beneficial ownership with intent to influence or control to disclose. Schedule 13G is the passive 5% disclosure (no intent to influence). Form 4 reports insider transactions within 2 business days. Each captures different information, has different thresholds, and tells you different things about institutional positioning.

This guide explains the four major filing types, their thresholds, what triggers each, and how to read them together for a complete picture of institutional ownership.

Form 13F-HR: The institutional holdings filing

Form 13F-HR is filed quarterly by institutional investment managers exercising discretion over $100+ million in US-listed Section 13(f) securities. The filing deadline is 45 days after the end of each calendar quarter.

What it captures:

• Long positions in US-listed equities (stocks, ETFs, ADRs).
• Share counts, reported values, voting authority.
• Position concentrations and quarter-over-quarter changes.

What it does NOT capture:

• Short positions, derivatives, options, futures.
• Private equity, real estate, commodities, fixed income.
• Cash holdings.
• International positions.
• Positions below the share-count minimum or in non-listed securities.

Schedule 13D: Activist beneficial ownership disclosure

Schedule 13D is required when any person or entity acquires 5%+ beneficial ownership of a Section 13(d) reporting issuer with intent to influence or control the company. The filing must be made within 10 days of crossing the 5% threshold and amended for material changes (typically thresholds of 1%+ in position size).

What 13D captures:

• Beneficial ownership percentage (computed on a fully diluted basis including derivatives).
• Identity of the filer and intent disclosure.
• Specific proposals or actions the filer intends to pursue (proxy fight, board nominees, M&A advocacy, etc.).
• Source of funds for the acquisition.
• Trades in the security within 60 days of filing.

13D is the activist's playbook documentation. Carl Icahn's 13D filings on JetBlue, Southwest Gas, IFF, AEP, etc. each document the activist thesis publicly.

Schedule 13G: Passive 5% disclosure

Schedule 13G is the passive alternative to 13D. Filed when a person or entity acquires 5%+ beneficial ownership without intent to influence or control. The reporting cadence is annual (within 45 days of year-end) or upon trigger events (crossing 10%, 20% milestones).

13G filers include passive index funds (Vanguard Group, BlackRock Finance), employee benefit trustee entities (Newport Trust, Greenleaf Trust for Stryker family), founder-family trusts (Hershey Trust at 96%+ HSY ownership), and corporate treasury holdings.

Form 4: Insider transactions

Form 4 reports transactions by Section 16 insiders (officers, directors, 10%+ beneficial owners) within 2 business days. The filing covers individual transactions: purchases, sales, option exercises, RSU vests, gifts, conversions.

Form 4 transaction codes:

• S — Open-market sale
• P — Open-market purchase (rarest, highest-information)
• M — Option exercise
• F — Tax withholding at RSU vest
• A — Award/grant
• G — Gift/transfer
• C — Conversion (Class B to A, etc.)
• D — Non-market disposition

How the four Forms interact

Reading institutional ownership requires reading all four Forms together:

The Form 4 + Schedule 13G/A cross-check (multi-class founder)

Form 4 reports direct Class A insider ownership after each transaction. Schedule 13G/A reports total beneficial ownership including indirect holdings (family trusts, foundations). Joe Mansueto's Form 4 shows 8.09M direct shares; his Schedule 13G/A shows 14.91M shares at 37.5% beneficial ownership. Reading only Form 4 misses 6.82M shares of indirect ownership.

The 13F-HR + Schedule 13G cross-check

Form 13F-HR reports the investment manager's discretionary holdings. Schedule 13G reports total beneficial ownership when 5%+ of a single issuer. Vanguard's 13F-HR captures roughly $4 trillion in US equity holdings spread across thousands of names; Vanguard's separate Schedule 13G filings document individual positions where it crosses 5% beneficial ownership.

The 13D vs 13G distinction

Schedule 13D and Schedule 13G are mutually exclusive at any moment for any single position. A holder can convert from 13G to 13D when intent changes (e.g., when passive ownership becomes activist engagement). The conversion typically signals an upcoming public campaign — watch for 13G-to-13D filings as activist-engagement signals.

The 13F-HR + Form 4 cross-check (insider company)

For companies where the founder is also the CEO (Apple's Tim Cook, Nvidia's Jensen Huang, Tesla's Elon Musk), Form 4 captures the founder's individual transactions while the company's own 13F-HR (if it exceeds $100M in US-listed securities) captures any strategic corporate holdings. Nvidia's 60% Intel stake appears in Nvidia's 13F-HR; Jensen Huang's personal Nvidia stock transactions appear on his Form 4 filings.

What thresholds tell you about ownership

Common misreads

Three errors:

1. Reading only Form 13F-HR for total institutional ownership. 13F captures only listed equity holdings of $100M+ investment managers. Individual block holders below the institutional threshold or in non-listed securities are missed.
2. Confusing 13D and 13G at the same threshold. Both trigger at 5% beneficial ownership, but the intent disclosure distinguishes activist (13D) from passive (13G) positioning. Conversion from 13G to 13D is the activist-trigger signal.
3. Treating Form 4 Table I as the complete insider position. Form 4 Table I reports direct non-derivative ownership. Form 4 Table II reports derivative securities. Schedule 13G/A reports total beneficial ownership. All three sometimes differ materially for founder-led companies with dual-class structures.

For real-time tracking across all four Form types, see the institutional signals feed. For related reading techniques on specific filer-type identification, see our explainer hub.