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Plain English guides

Everything you need to know about following smart money. No jargon, no fluff.

Featured collection · 9 essays
Famous trades — public-record case studies

Berkshire/Coca-Cola · Berkshire/Apple · Berkshire/BAC 2011 · Tepper/2009 banks · Burry/Big Short · Ackman/Herbalife · Soros-Druckenmiller/GBP · Munger/Costco · Icahn/Apple. Each trade reconstructable from SEC EDGAR alone.

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All essays (36)
The Superinvestor Handbook

The full 10-section guide — 13F filings, conviction signals, copy-trading myths, and the honest limits of smart-money data. ~15 min read.

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What is a 13F filing?

Plain English guide to SEC Form 13F. What's in it, when it drops, what it does and doesn't show.

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How to read a 13F filing in 5 minutes

Step-by-step: open any 13F on EDGAR and know what every field means. With real Berkshire examples.

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What is alpha?

The hedge fund edge explained without jargon. Why 85% of managers have none — and what the 15% have in common.

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The 45-day lag in 13F filings

Why every 13F is six weeks late by design — and how to use lagged data without getting burned.

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The Warren Buffett method

Which Buffett principles are actually transferable to a retail account, and which depend on structural edges you don't have.

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The copy-trading myth

Why mechanically copying Buffett's 13F underperforms the underlying portfolio.

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What is a Conviction Score?

How to tell a real bet from index padding. The −100..+100 scale explained.

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Survivorship bias in hedge funds

Why every hedge fund performance number you read is probably an overestimate — and how missing dead funds distorts 13F signals.

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13F vs 13D vs 13G

Three SEC filings, three signals. The difference between a quarterly portfolio snapshot, an activist disclosure, and a passive big-stake filing — and how to read each one.

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Form 4 vs 13F — insider trades vs institutional portfolios

Two SEC filings, two completely different signals. Form 4 is a 2-day insider receipt; 13F is a 45-day institutional portfolio snapshot. Speed, scope, signal strength, and when to read each one.

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Do 13F signals actually predict returns? We ran the backtest

Original research — April 2026. We backtested our own ConvictionScore over 221 ticker-quarter pairs across 4 quarters. Result: r = −0.12, no predictive signal. Top-decile BUYs underperformed SPY by 5 pts; bottom-decile SELLs beat it by 24 pts. Why, and what to use 13F data for instead.

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Buybacks vs dividends — what's the real difference?

Both return capital. One is flashier; the other is more tax-efficient. The honest tradeoffs on tax, flexibility, and long-term compounding.

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How to read buyback disclosures

Where the real buyback numbers live in SEC 10-K, 10-Q, and 8-K filings — plus how to spot debt-funded financial engineering and stock-based-comp distortions.

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13D vs 13G — what the difference actually means

Plain-English guide: when an investor crosses 5%, which filing they pick reveals their intent. Activist (13D) means board fights. Passive (13G) means index hold.

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Short interest, days-to-cover, and squeeze setups

What short interest actually measures, how days-to-cover is calculated, and why high short interest is BOTH a squeeze setup AND a smart-money signal.

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How the STOCK Act works — Congressional stock trading

What the STOCK Act of 2012 actually requires, why disclosures show ranges (not exact amounts), how late filings are penalized, and how to read the disclosures.

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ETF overlap — why owning multiple ETFs doesn't diversify

What overlap actually means, how to measure it, and why owning VOO + VTI + QQQ + SPY delivers far less diversification than you think.

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What is the Insider Score?

The −100..+100 metric synthesizing Form 4 insider transactions across the tracked-superinvestor universe. Methodology, math, what the score does and doesn't mean.

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What is the Event Score?

8-K material events scored on a unified scale. Item taxonomy mapping, weight calibration, and how to read the live feed.

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The SEC signals trilogy — 13F + Form 4 + 8-K

The three SEC filing types HoldLens reads together. Why no single filing tells the whole story, and how the trilogy synthesizes into one ConvictionScore.

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What is SEC EDGAR?

The SEC's public filing database — the canonical source for every 10-K, 13F, Form 4, 8-K filed since 1993. How to use it, what to ignore, where it falls short.

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What is a CUSIP?

The 9-character identifier that uniquely names every North American security. Structure, math, why tickers aren't enough for 13F reporting.

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Proxy voting and DEF 14A

The definitive proxy statement — what to read, what to skip, how to vote informed. Read the 1-page summary in 10 minutes.

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The 13(f) securities list — what counts as a 13F holding?

The SEC's quarterly Official List defining what shows up on 13F. ~17,000 securities in scope; shorts, bonds, foreign equities, most derivatives all out of scope.

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Rule 144 holding period — when insiders can sell

6 months for reporting issuers; 12 months for non-reporting. Volume limits, manner-of-sale, and three practical reading angles for tracking insider supply.

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Warren Buffett's Q1 2026 13F moves

Berkshire's most active 13F quarter since 2024 — Delta Air Lines re-entry, Alphabet Class C add, Macy's + NYT adds, full exits of Visa + Mastercard + UnitedHealth + Aon, Chevron + Constellation trims. EDGAR-reconstructable.

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Warren Buffett's Coca-Cola trade

Berkshire's 1988-89 KO purchase — $1.3B invested, today ~$28B position, untouched for 37 years. Trade mechanics + 13F-traceable accumulation timeline.

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Warren Buffett's Apple position

Berkshire's 2016-onward Apple accumulation — built into the firm's largest-ever equity position. Q1 2016 entry · Q2/Q3 2024 partial trim · still Berkshire's #1 holding. Full 13F-traceable timeline.

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Warren Buffett's Bank of America 2011 deal

August 2011: $5B preferred + warrants for 700M BAC shares at $7.14 strike. The cleanest example of Buffett's 'structured private investment' template, alongside Goldman 2008 + GE 2008. ~$13B paper gain at 2017 warrant exercise; top-3 Berkshire holding through 2024.

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David Tepper's 2009 bank trade

Q1 2009: Appaloosa Management bought ~$2B of Bank of America + Citigroup + AIG common stock at distressed prices (BAC ~$3, C under $1). Returned ~$7B as the implicit TARP+CPP government floor proved Tepper's nationalization-tail-risk thesis right. ~$4B personal payday — second-highest single-year hedge-fund individual payout in modern history at the time, behind only Paulson 2007.

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Michael Burry's Big Short

Scion Capital's 2005-2008 subprime CDS trade returned ~489% net. The canonical case study in why 13F-based research has structural blind spots.

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Bill Ackman's Herbalife short

Pershing Square's six-year activist short campaign — entered 2012, closed at a loss in 2018. What the public-record trail reveals.

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Black Wednesday — Soros, Druckenmiller, and the pound trade

September 16, 1992. Quantum Fund's $1B-in-a-day short of the British pound that forced the UK to exit the ERM. The FX/short/derivative gap to 13F.

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Charlie Munger's Costco position

1997 to 2023. Munger's 26-year hold + board seat — the canonical concentrated long-duration value position, fully traceable through SEC Form 4 + 13F + DEF 14A filings.

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Carl Icahn's Apple buyback campaign

2013-2016 long-side activism — $3.6B position, public open letter to Tim Cook, ~$2B realized gain. The cleanest SEC-filing-trail activist case in modern markets.

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