{ "name": "HoldLens /learn index", "version": "v1", "description": "Machine-readable index of every HoldLens /learn essay. Designed for LLM crawlers, research agents, and citation lookups. Each entry is canonical, public, and free to cite with attribution.", "base_url": "https://holdlens.com/learn", "count": 56, "license": "All content © HoldLens / editnative.com. Free to cite with link attribution to the canonical URL. Not investment advice — historical SEC-filing analysis only.", "topics": [ "SEC filings (10-K, 10-Q, 13F, 8-K, Form 4, DEF 14A, etc.)", "Superinvestor portfolios (Buffett, Ackman, Burry, Klarman, Druckenmiller, and 26 more)", "Concentrated value investing and conviction signals", "Famous historical trades (Coca-Cola 1988, Big Short, Black Wednesday, Costco, Herbalife, Apple buybacks)", "Activist investing (13D vs 13G, board seats, public letters)", "Buybacks vs dividends, short interest, congressional stock trading" ], "primary_data_source": "SEC EDGAR (https://www.sec.gov/edgar/)", "related_apis": { "managers": "https://holdlens.com/api/v1/managers.json", "best_now": "https://holdlens.com/api/v1/best-now.json", "overlap": "https://holdlens.com/api/v1/overlap.json", "index": "https://holdlens.com/api/v1/index.json" }, "sister_property": { "name": "SecFilingDex", "url": "https://secfilingdex.com", "description": "Companion encyclopedia of SEC filing types (10-K, 13F-HR, Form 4, DEF 14A, S-1, F-1, and more). HoldLens cites SecFilingDex for filing-discovery and form-mechanics; SecFilingDex cites HoldLens for tracked-superinvestor examples." }, "collections": { "famous_trades": { "name": "Famous trades — public-record case studies", "description": "Eight historical trades reconstructable from SEC EDGAR alone (Berkshire/KO 1988, Berkshire/Apple 2016-onward, Berkshire/BAC 2011 preferred+warrants, Burry/Big Short 2005-08, Ackman/Herbalife 2012-18, Soros-Druckenmiller/GBP 1992, Munger/Costco 1997-2023, Icahn/Apple 2013-16). Each essay traces the trade through 13F, Form 4, and DEF 14A filings.", "slugs": [ "buffett-coca-cola-trade", "buffett-apple-position", "buffett-bank-of-america-2011", "tepper-bank-stocks-2009", "burry-big-short", "ackman-herbalife-short", "soros-druckenmiller-gbp-1992", "munger-costco-lifetime-hold", "icahn-apple-buyback-campaign" ] }, "sec_filing_mechanics": { "name": "SEC filing mechanics", "description": "Plain-English guides to the SEC forms that produce HoldLens's data: 13F (institutional holdings), Form 4 (insider trades), DEF 14A (proxies), 13D/13G (5%+ stakes), Rule 144 (insider sales).", "slugs": [ "edgar-explained", "what-is-a-13f", "how-to-read-a-13f", "45-day-lag-explained", "13f-vs-13d-vs-13g", "13d-vs-13g-activist-filings", "13f-securities-list", "form-4-vs-13f", "proxy-voting-def-14a", "rule-144-holding-period", "cusip-explained" ] }, "signals_and_methodology": { "name": "HoldLens signals + methodology", "description": "How HoldLens computes ConvictionScore, InsiderScore, Event Score, and why no single SEC filing tells the whole story.", "slugs": [ "conviction-score-explained", "insider-score-explained", "event-score-explained", "sec-signals-trilogy", "do-hedge-fund-signals-work", "what-is-alpha", "copy-trading-myth", "survivorship-bias-in-hedge-funds", "superinvestor-handbook", "warren-buffett-method" ] }, "capital_allocation": { "name": "Capital allocation + corporate finance", "description": "Buybacks, dividends, short interest, ETF overlap, congressional stock trading — adjacent topics for serious public-markets readers.", "slugs": [ "buybacks-vs-dividends", "how-to-read-buyback-disclosures", "short-interest-explained", "etf-overlap-explained", "congressional-stock-trading-stock-act" ] } }, "last_updated": "2026-07-03", "articles": [ { "slug": "superinvestor-handbook", "title": "The Superinvestor Handbook", "description": "The full 10-section guide — 13F filings, conviction signals, copy-trading myths.", "url": "https://holdlens.com/learn/superinvestor-handbook", "canonical": "https://holdlens.com/learn/superinvestor-handbook" }, { "slug": "what-is-a-13f", "title": "What is a 13F filing?", "description": "Plain English guide to SEC Form 13F.", "url": "https://holdlens.com/learn/what-is-a-13f", "canonical": "https://holdlens.com/learn/what-is-a-13f" }, { "slug": "how-to-read-a-13f", "title": "How to read a 13F in 5 minutes", "description": "Step-by-step with real Berkshire examples.", "url": "https://holdlens.com/learn/how-to-read-a-13f", "canonical": "https://holdlens.com/learn/how-to-read-a-13f" }, { "slug": "how-to-interpret-changes-in-positions", "title": "How to interpret position changes in a 13F", "description": "New stake, exit, add, trim — compare share counts not dollar values, weigh by portfolio share.", "url": "https://holdlens.com/learn/how-to-interpret-changes-in-positions", "canonical": "https://holdlens.com/learn/how-to-interpret-changes-in-positions" }, { "slug": "how-to-find-hedge-fund-holdings", "title": "How to find what hedge funds are buying", "description": "The free way to pull holdings from SEC EDGAR — and the limits.", "url": "https://holdlens.com/learn/how-to-find-hedge-fund-holdings", "canonical": "https://holdlens.com/learn/how-to-find-hedge-fund-holdings" }, { "slug": "who-files-a-13f", "title": "Who has to file a 13F?", "description": "The $100M threshold, who qualifies as an institutional manager, and who is exempt.", "url": "https://holdlens.com/learn/who-files-a-13f", "canonical": "https://holdlens.com/learn/who-files-a-13f" }, { "slug": "what-is-a-superinvestor", "title": "What is a superinvestor?", "description": "From Buffett's 1984 Graham-and-Doddsville essay to modern 13F tracking — who earns the term.", "url": "https://holdlens.com/learn/what-is-a-superinvestor", "canonical": "https://holdlens.com/learn/what-is-a-superinvestor" }, { "slug": "what-is-an-insider", "title": "What is a corporate insider?", "description": "Officers, directors, 10%+ owners — SEC Section 16, Form 4, and legal vs illegal.", "url": "https://holdlens.com/learn/what-is-an-insider", "canonical": "https://holdlens.com/learn/what-is-an-insider" }, { "slug": "why-13f-doesnt-show-shorts", "title": "Why doesn't a 13F show short positions?", "description": "13Fs are long-only — shorts, swaps, and hedges are invisible.", "url": "https://holdlens.com/learn/why-13f-doesnt-show-shorts", "canonical": "https://holdlens.com/learn/why-13f-doesnt-show-shorts" }, { "slug": "what-is-alpha", "title": "What is alpha?", "description": "The hedge fund edge explained without jargon.", "url": "https://holdlens.com/learn/what-is-alpha", "canonical": "https://holdlens.com/learn/what-is-alpha" }, { "slug": "45-day-lag-explained", "title": "The 45-day lag in 13F filings", "description": "Why every 13F is six weeks late by design.", "url": "https://holdlens.com/learn/45-day-lag-explained", "canonical": "https://holdlens.com/learn/45-day-lag-explained" }, { "slug": "warren-buffett-method", "title": "The Warren Buffett method", "description": "Which Buffett principles are actually transferable.", "url": "https://holdlens.com/learn/warren-buffett-method", "canonical": "https://holdlens.com/learn/warren-buffett-method" }, { "slug": "copy-trading-myth", "title": "The copy-trading myth", "description": "Why mechanically copying Buffett underperforms the underlying portfolio.", "url": "https://holdlens.com/learn/copy-trading-myth", "canonical": "https://holdlens.com/learn/copy-trading-myth" }, { "slug": "conviction-score-explained", "title": "What is a Conviction Score?", "description": "How to tell a real bet from index padding.", "url": "https://holdlens.com/learn/conviction-score-explained", "canonical": "https://holdlens.com/learn/conviction-score-explained" }, { "slug": "survivorship-bias-in-hedge-funds", "title": "Survivorship bias in hedge funds", "description": "Why every hedge fund performance number you read is probably an overestimate.", "url": "https://holdlens.com/learn/survivorship-bias-in-hedge-funds", "canonical": "https://holdlens.com/learn/survivorship-bias-in-hedge-funds" }, { "slug": "13f-vs-13d-vs-13g", "title": "13F vs 13D vs 13G", "description": "Three SEC filings, three signals.", "url": "https://holdlens.com/learn/13f-vs-13d-vs-13g", "canonical": "https://holdlens.com/learn/13f-vs-13d-vs-13g" }, { "slug": "form-4-vs-13f", "title": "Form 4 vs 13F", "description": "Insider trades vs institutional portfolios — two SEC filings, two different signals.", "url": "https://holdlens.com/learn/form-4-vs-13f", "canonical": "https://holdlens.com/learn/form-4-vs-13f" }, { "slug": "how-do-hedge-funds-disclose-positions", "title": "How do hedge funds disclose their positions?", "description": "13F, 13D, 13G, Form 4 — the full required-vs-voluntary matrix, and what never gets disclosed.", "url": "https://holdlens.com/learn/how-do-hedge-funds-disclose-positions", "canonical": "https://holdlens.com/learn/how-do-hedge-funds-disclose-positions" }, { "slug": "do-hedge-fund-signals-work", "title": "Do 13F signals actually predict returns?", "description": "Original backtest — 221 ticker-quarter pairs, r = −0.12, no predictive signal.", "url": "https://holdlens.com/learn/do-hedge-fund-signals-work", "canonical": "https://holdlens.com/learn/do-hedge-fund-signals-work" }, { "slug": "buybacks-vs-dividends", "title": "Buybacks vs dividends", "description": "Both return capital. Tax + flexibility + long-term compounding tradeoffs.", "url": "https://holdlens.com/learn/buybacks-vs-dividends", "canonical": "https://holdlens.com/learn/buybacks-vs-dividends" }, { "slug": "how-to-read-buyback-disclosures", "title": "How to read buyback disclosures", "description": "Where the real numbers live in 10-K, 10-Q, and 8-K filings.", "url": "https://holdlens.com/learn/how-to-read-buyback-disclosures", "canonical": "https://holdlens.com/learn/how-to-read-buyback-disclosures" }, { "slug": "13d-vs-13g-activist-filings", "title": "13D vs 13G — activist vs passive", "description": "When an investor crosses 5%, which filing they pick reveals intent.", "url": "https://holdlens.com/learn/13d-vs-13g-activist-filings", "canonical": "https://holdlens.com/learn/13d-vs-13g-activist-filings" }, { "slug": "short-interest-explained", "title": "Short interest + squeeze setups", "description": "What short interest measures, days-to-cover math, smart-money signal layer.", "url": "https://holdlens.com/learn/short-interest-explained", "canonical": "https://holdlens.com/learn/short-interest-explained" }, { "slug": "congressional-stock-trading-stock-act", "title": "Congressional stock trading and the STOCK Act", "description": "What the STOCK Act requires, how disclosures show ranges, how to read them.", "url": "https://holdlens.com/learn/congressional-stock-trading-stock-act", "canonical": "https://holdlens.com/learn/congressional-stock-trading-stock-act" }, { "slug": "etf-overlap-explained", "title": "ETF overlap explained", "description": "Why owning VOO + VTI + QQQ + SPY delivers far less diversification than you think.", "url": "https://holdlens.com/learn/etf-overlap-explained", "canonical": "https://holdlens.com/learn/etf-overlap-explained" }, { "slug": "insider-score-explained", "title": "What is the Insider Score?", "description": "The Form 4 insider-transaction metric synthesizing the tracked-superinvestor universe.", "url": "https://holdlens.com/learn/insider-score-explained", "canonical": "https://holdlens.com/learn/insider-score-explained" }, { "slug": "event-score-explained", "title": "What is the Event Score?", "description": "8-K material events on a unified scale; item taxonomy + weight calibration.", "url": "https://holdlens.com/learn/event-score-explained", "canonical": "https://holdlens.com/learn/event-score-explained" }, { "slug": "sec-signals-trilogy", "title": "The SEC signals trilogy", "description": "13F + Form 4 + 8-K read together; why no single filing tells the whole story.", "url": "https://holdlens.com/learn/sec-signals-trilogy", "canonical": "https://holdlens.com/learn/sec-signals-trilogy" }, { "slug": "edgar-explained", "title": "What is SEC EDGAR?", "description": "The SEC's public filing database — every 10-K, 13F, Form 4 since 1993, free.", "url": "https://holdlens.com/learn/edgar-explained", "canonical": "https://holdlens.com/learn/edgar-explained" }, { "slug": "cusip-explained", "title": "What is a CUSIP?", "description": "The 9-character identifier behind every 13F line item.", "url": "https://holdlens.com/learn/cusip-explained", "canonical": "https://holdlens.com/learn/cusip-explained" }, { "slug": "proxy-voting-def-14a", "title": "Proxy voting and DEF 14A", "description": "The definitive proxy statement — read the 1-page summary in 10 minutes.", "url": "https://holdlens.com/learn/proxy-voting-def-14a", "canonical": "https://holdlens.com/learn/proxy-voting-def-14a" }, { "slug": "13f-securities-list", "title": "The 13(f) securities list", "description": "What counts as a 13F holding — and what doesn't.", "url": "https://holdlens.com/learn/13f-securities-list", "canonical": "https://holdlens.com/learn/13f-securities-list" }, { "slug": "rule-144-holding-period", "title": "Rule 144 holding period", "description": "When corporate insiders can sell — 6-month vs 12-month rules.", "url": "https://holdlens.com/learn/rule-144-holding-period", "canonical": "https://holdlens.com/learn/rule-144-holding-period" }, { "slug": "superinvestors-q1-2026-moves", "title": "What superinvestors bought in Q1 2026", "description": "13 hedge fund 13F filings read together — the AI trade split four ways, plus the value investors, the deep-value bets, and the net sellers.", "url": "https://holdlens.com/learn/superinvestors-q1-2026-moves", "canonical": "https://holdlens.com/learn/superinvestors-q1-2026-moves" }, { "slug": "buffett-q1-2026-moves", "title": "Warren Buffett's Q1 2026 13F moves", "description": "Berkshire's most active quarter in years — Delta re-entry + Alphabet add + V/MA/UNH/AON exits.", "url": "https://holdlens.com/learn/buffett-q1-2026-moves", "canonical": "https://holdlens.com/learn/buffett-q1-2026-moves" }, { "slug": "ackman-q1-2026-moves", "title": "Bill Ackman's Q1 2026 13F moves", "description": "Microsoft new at 15% of book, Alphabet near-exit — Pershing Square's most assertive entry in years.", "url": "https://holdlens.com/learn/ackman-q1-2026-moves", "canonical": "https://holdlens.com/learn/ackman-q1-2026-moves" }, { "slug": "tepper-q1-2026-moves", "title": "David Tepper's Q1 2026 13F moves", "description": "Amazon to #1, China unwind, memory + semis adds across Appaloosa's book.", "url": "https://holdlens.com/learn/tepper-q1-2026-moves", "canonical": "https://holdlens.com/learn/tepper-q1-2026-moves" }, { "slug": "druckenmiller-q1-2026-moves", "title": "Stanley Druckenmiller's Q1 2026 13F moves", "description": "Natera at 18%, YPF + Alcoa + STMicro adds — diversification pivot, AUM down 25%.", "url": "https://holdlens.com/learn/druckenmiller-q1-2026-moves", "canonical": "https://holdlens.com/learn/druckenmiller-q1-2026-moves" }, { "slug": "hohn-q1-2026-moves", "title": "Chris Hohn's Q1 2026 13F moves", "description": "TCI guts Microsoft, deepens GE + Visa to 58% of a famously concentrated book.", "url": "https://holdlens.com/learn/hohn-q1-2026-moves", "canonical": "https://holdlens.com/learn/hohn-q1-2026-moves" }, { "slug": "li-lu-q1-2026-moves", "title": "Li Lu's Q1 2026 13F moves", "description": "Himalaya cuts its 15-year Bank of America anchor 71% (28.6%→4.6%); opens Moody's, MSCI, Tencent Music, H&R Block.", "url": "https://holdlens.com/learn/li-lu-q1-2026-moves", "canonical": "https://holdlens.com/learn/li-lu-q1-2026-moves" }, { "slug": "coleman-q1-2026-moves", "title": "Chase Coleman's Q1 2026 13F moves", "description": "Tiger Global piles into AI hardware (Nvidia, TSMC +49%, Applied Materials +85%) and halves Microsoft to 4.1%; trims software + fintech.", "url": "https://holdlens.com/learn/coleman-q1-2026-moves", "canonical": "https://holdlens.com/learn/coleman-q1-2026-moves" }, { "slug": "halvorsen-q1-2026-moves", "title": "Andreas Halvorsen's Q1 2026 13F moves", "description": "Viking pushes Visa to #1 (+59%), builds quality industrials (Danaher, Fortive, Thermo Fisher +110%, Air Products new); trims Microsoft + Alphabet. New Apple.", "url": "https://holdlens.com/learn/halvorsen-q1-2026-moves", "canonical": "https://holdlens.com/learn/halvorsen-q1-2026-moves" }, { "slug": "mandel-q1-2026-moves", "title": "Stephen Mandel's Q1 2026 13F moves", "description": "Lone Pine bets on AI's infrastructure — Vistra + Talen (power), ASML + new Teradyne/Corning/MasTec — while halving TSMC.", "url": "https://holdlens.com/learn/mandel-q1-2026-moves", "canonical": "https://holdlens.com/learn/mandel-q1-2026-moves" }, { "slug": "klarman-q1-2026-moves", "title": "Seth Klarman's Q1 2026 13F moves", "description": "Baupost makes Amazon its top holding (+47%), adds Alphabet + Ferguson, opens new Aon / Visa / Teleflex.", "url": "https://holdlens.com/learn/klarman-q1-2026-moves", "canonical": "https://holdlens.com/learn/klarman-q1-2026-moves" }, { "slug": "pabrai-q1-2026-moves", "title": "Mohnish Pabrai's Q1 2026 13F moves", "description": "A three-stock US book — 68% met coal (Warrior + Alpha), Transocean trimmed, Valaris exited. The most concentrated 13F we track.", "url": "https://holdlens.com/learn/pabrai-q1-2026-moves", "canonical": "https://holdlens.com/learn/pabrai-q1-2026-moves" }, { "slug": "terry-smith-q1-2026-moves", "title": "Terry Smith's Q1 2026 13F moves", "description": "Fundsmith trims almost its entire US book — Marriott, Stryker, Visa, Alphabet, Pfizer all reduced. A uniform pullback.", "url": "https://holdlens.com/learn/terry-smith-q1-2026-moves", "canonical": "https://holdlens.com/learn/terry-smith-q1-2026-moves" }, { "slug": "ainslie-q1-2026-moves", "title": "Lee Ainslie's Q1 2026 13F moves", "description": "Maverick trims broadly (Carpenter −61%, MasTec −65%, Live Nation −73%) and opens new Meta + Alphabet + Hut 8.", "url": "https://holdlens.com/learn/ainslie-q1-2026-moves", "canonical": "https://holdlens.com/learn/ainslie-q1-2026-moves" }, { "slug": "buffett-coca-cola-trade", "title": "Warren Buffett's Coca-Cola trade", "description": "Berkshire's 1988-89 KO purchase — $1.3B → $28B+ position, untouched for 37 years.", "url": "https://holdlens.com/learn/buffett-coca-cola-trade", "canonical": "https://holdlens.com/learn/buffett-coca-cola-trade" }, { "slug": "buffett-apple-position", "title": "Warren Buffett's Apple position", "description": "Berkshire's 2016-onward AAPL accumulation — largest equity position in firm history. Q1 2016 entry · 2024 partial trim · ongoing.", "url": "https://holdlens.com/learn/buffett-apple-position", "canonical": "https://holdlens.com/learn/buffett-apple-position" }, { "slug": "buffett-bank-of-america-2011", "title": "Warren Buffett's Bank of America 2011 deal", "description": "The $5B preferred + 700M-share warrants at $7.14 strike. ~$13B paper gain at 2017 warrant exercise. Top-3 Berkshire holding ever since.", "url": "https://holdlens.com/learn/buffett-bank-of-america-2011", "canonical": "https://holdlens.com/learn/buffett-bank-of-america-2011" }, { "slug": "tepper-bank-stocks-2009", "title": "David Tepper's 2009 bank trade", "description": "Appaloosa Management's March 2009 distressed-bank bet on BAC + Citigroup + AIG common stock. ~$7B returned. $4B personal payday — second-highest single-year hedge-fund payout in modern history.", "url": "https://holdlens.com/learn/tepper-bank-stocks-2009", "canonical": "https://holdlens.com/learn/tepper-bank-stocks-2009" }, { "slug": "burry-big-short", "title": "Michael Burry's Big Short", "description": "Scion Capital's 2005-2008 subprime CDS trade — ~489% net return.", "url": "https://holdlens.com/learn/burry-big-short", "canonical": "https://holdlens.com/learn/burry-big-short" }, { "slug": "ackman-herbalife-short", "title": "Bill Ackman's Herbalife short", "description": "Pershing Square's 2012-2018 multi-year activist short campaign.", "url": "https://holdlens.com/learn/ackman-herbalife-short", "canonical": "https://holdlens.com/learn/ackman-herbalife-short" }, { "slug": "soros-druckenmiller-gbp-1992", "title": "Black Wednesday — Soros, Druckenmiller, and the pound trade", "description": "The single-day macro trade that broke the Bank of England.", "url": "https://holdlens.com/learn/soros-druckenmiller-gbp-1992", "canonical": "https://holdlens.com/learn/soros-druckenmiller-gbp-1992" }, { "slug": "munger-costco-lifetime-hold", "title": "Charlie Munger's Costco position", "description": "1997-2023 hold + board seat — the canonical concentrated long-duration value position.", "url": "https://holdlens.com/learn/munger-costco-lifetime-hold", "canonical": "https://holdlens.com/learn/munger-costco-lifetime-hold" }, { "slug": "icahn-apple-buyback-campaign", "title": "Carl Icahn's Apple buyback campaign", "description": "2013-2016 long-side activism — public letter to Tim Cook, ~$2B realized gain.", "url": "https://holdlens.com/learn/icahn-apple-buyback-campaign", "canonical": "https://holdlens.com/learn/icahn-apple-buyback-campaign" } ] }