Updated May 15, 2026 · 633 articles
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Educational guides about 13F filings, insider trading, institutional investing, and how to track smart money moves.
M&A-Driven 13F Positions: Deal Consideration Equity Stakes
MUFG holds 76% of its US 13F in US Bancorp from the 2022 Union Bank sale. Chevron's 2025 Hess acquisition produced legacy founder-family positions. Strategic-stake equity consideration from M&A deals creates a distinctive 13F category requiring different reading rules.
Sarah MitchellReading the 13F Holder Tail: Beyond the Top 10
The top 10 holders of a stock are usually passive index funds plus a handful of mega-cap-tracking active managers. The real active conviction lives in ranks 30-100 of the holder table. Here's how to read past the index sleeve for the discretionary signal.
Sarah MitchellCross-Checking 13F + 13D + Form 4 + 990-PF: The Full Picture
Each SEC and IRS filing captures different information at different thresholds. Reading institutional ownership correctly requires cross-referencing Form 13F-HR (institutional holdings), Schedule 13D/G (5%+ beneficial), Form 4 (insider transactions), and IRS 990-PF (foundation endowment). Here's the framework.
Sarah MitchellSovereign Pre-IPO Stakes: PIF, Temasek, SoftBank Vision
Saudi PIF holds Uber at 46% of its US 13F — the 2016 pre-IPO investment. Temasek holds BlackRock at 17% strategic. SoftBank Vision Fund's UK entity holds Coupang at 68%. Sovereign pre-IPO strategic stakes appear at extreme concentrations across US 13F filings.
Sarah MitchellStrategic Bank Stakes: MUFG/USB, BNP/BAML, Mizuho/JPM Reading
MUFG holds 75.93% of its 13F in US Bancorp from the 2022 Union Bank sale. Other Japanese and European banks hold strategic stakes in US banks. These structural cross-bank positions require different reading rules than active institutional positioning.
Sarah MitchellReading International Quality 13Fs: BLS, PineStone, EdgePoint
BLS Capital (Denmark) runs 95% of $2.94B in 10 quality compounders. PineStone (Quebec) runs 67% in 10 names. EdgePoint (Toronto) runs 68% in deep-value contrarian. International quality-discipline managers run distinctively concentrated US-equity books.
Sarah MitchellReading 13F Holder Shifts Through Operational Cycles
UNH lost institutional conviction holders through the 2024 Change Healthcare cyber breach. Pfizer's Fisher Asset Management 1% portfolio bet anchored through the post-COVID revenue cliff. Visa's holders held through Durbin and CCCA legislative cycles. Here's how to read holder-table shifts as cycle signals.
Sarah MitchellVisa-Mastercard Duopoly: Reading the Payments Network in 13Fs
Mastercard Foundation holds 96.84% of its 13F in MA. PineStone runs 6.36% in MA. Schroder runs 1.93%. Mitsubishi UFJ AM runs 2.74x index in V. Payment-network duopoly stocks attract structurally different institutional concentration patterns. Here's why and how to read them.
Sarah MitchellBerkshire's Long-Term Compounders: KO, AXP, BAC, AAPL Reading
Berkshire Hathaway holds Coca-Cola at 10.20% portfolio (1988 entry), Bank of America at 10.38% (2011 entry), American Express at substantial concentration (1991 entry), and Apple at the largest weight (2016 entry). Reading Buffett's long-term compounders requires understanding what each position represents.
Sarah MitchellPost-Merger Form 4: When Insiders Switch Tickers
John Hess now files Form 4 transactions in Chevron stock — not Hess Corp — following the 2025 merger. Pinpointing post-merger insider activity requires tracking the conversion ratio and the new ticker. Here's the framework.
Sarah MitchellCharitable Foundation 13Fs: Mastercard Foundation, Gates, Buffett
The Mastercard Foundation holds $32.6 billion in MA at 96.84% of its 13F. The Gates Foundation Trust, Buffett's Susan Thompson Foundation, and other large charitable foundations file similar concentrated structures. Reading them requires understanding the founding-gift mechanics and perpetual endowment mandates.
Sarah MitchellHealthcare Cybersecurity in 13Fs: UNH, MRK, JNJ Risk Reading
Healthcare-payor and pharma R&D data is one of the highest-value targets in the AI cybersecurity threat cycle. UNH lost $2B+ in the 2024 Change Healthcare breach. Pharma R&D and clinical-trial data are next. Here's how institutional positioning reflects the risk.
Sarah Mitchell13F Filing Thresholds: $100M, 5%, 13D vs 13G Decoder
Section 13(f) requires Form 13F-HR for $100+ million in US-listed securities. Section 13(d) requires 13D filings above 5% beneficial ownership. Section 13(g) is passive 5% threshold. Each form captures different information at different thresholds. Here's the framework.
Sarah MitchellStrategic Minerals in 13F: Antimony, Rare Earths, Lithium Reading
Paulson holds Perpetua Resources at 24% portfolio — a US antimony mine pre-production. MP Materials and Lynas hold rare-earths positioning. Albemarle and SQM offer lithium exposure. Strategic-minerals 13F positions reflect US-China supply-chain tension. Here's how to read them.
Sarah MitchellNASH and Specialty Biotech in 13Fs: MDGL, ASND, ARGX, KRYS
Paulson holds Madrigal at 30% of portfolio. Avoro holds MDGL plus ASND, ARGX, KRYS at 12-10% each. NASH, rare-disease, and protein-degradation specialty biotech show up across multiple concentrated 13Fs. Here's how to read them.
Sarah MitchellOCIO 13F Filings: Outsourced-CIO Asset Allocation Decoded
Cambridge Associates' Q1 2026 13F is $6.31 billion entirely in ETFs. Russell Investments, Mercer, Aon, and BlackRock OCIO file similar structures. These are outsourced-CIO institutional asset allocations, not stock-picker books. Here's how to read them.
Sarah MitchellCross-Company Strategic Stakes in 13Fs: Nvidia, Apple, Salesforce
Nvidia holds 60% of its US 13F in Intel — a single strategic stake. Apple has held strategic stakes in Didi and other companies historically. Salesforce, Alphabet, Berkshire all hold meaningful cross-company stakes. Here's how to read them.
Sarah MitchellSusquehanna Owns B of UNH: Market Maker 13F Decoder
Susquehanna International Group holds $10.34 billion of UnitedHealth at 1.19% portfolio. Jane Street, Citadel Advisors, CTC, and Wolverine Trading hold similar large positions across high-options-volume stocks. These are not conviction positions — they are options inventory.
Sarah MitchellCapital Group Files 3 Separate 13Fs: Multi-Vehicle Guide
Capital Group holds $97.9 billion of Broadcom across three separately filed 13Fs (Capital World Investors, Capital Research Global Investors, Capital International Investors). Vanguard files 4+ separate entities. BlackRock, Fidelity, State Street all do the same. Reading single-firm-family conviction requires aggregating across vehicles.
Sarah MitchellSovereign Wealth Fund 13Fs: PIF, Norges Bank, GIC Reading Guide
Saudi Arabia's PIF holds Uber at 45.97% of its US 13F. Norges Bank runs $935B in diversified US equities. GIC, Temasek, ADIA, and Kuwait Investment Authority each file with distinctive structural fingerprints. Reading them requires different rules than standard active manager 13Fs.
Sarah Mitchell