Investor portfolios and ideas
Long reads on well-known investors and the economists who shaped investing: their ideas, and what the latest public stock reports (SEC Form 13F) of six real portfolios actually show, quarter by quarter.
Investor portfolios
Warren Buffett's portfolio: what Berkshire Hathaway really owns now
Five quarters of Berkshire's public stock holdings, from Apple and American Express to the surprise rise of Alphabet, set against the ideas Buffett took from Benjamin Graham, Philip Fisher and Charlie Munger.
Ray Dalio's Bridgewater: what its public stock portfolio shows, and what it hides
The world's largest hedge fund files a long list of US stocks and funds. Five quarters of that list, read against the All Weather idea of balancing a portfolio for every economic season.
Bill Ackman's Pershing Square: ten stocks, large bets and constant rotation
Pershing Square holds about ten large companies. Five quarters show a switch from Alphabet to Amazon, Meta and Microsoft, and what concentrated investing really looks like.
Stanley Druckenmiller's Duquesne: a big bet on one stock among ninety
Duquesne Family Office combines one very large position, dozens of small ones, and options on funds. Five quarters of the portfolio of a macro investor with one of the longest unbroken records.
Seth Klarman's Baupost: value investing in a market full of megacaps
A famous value investor who wrote a book about the margin of safety now owns Amazon and Alphabet. Five quarters of the Baupost portfolio and what the word value really means.
Mohnish Pabrai's Dalal Street: three stocks, two industries and a very simple idea
A tiny portfolio of unloved cyclical companies, managed in the spirit of 'heads I win, tails I don't lose much'. Five quarters of the most concentrated book we cover.
David Tepper's Appaloosa: a contrarian who now concentrates on Amazon, Micron and TSMC
A famous buyer of fear, known for buying banks in 2009, now runs a portfolio of about thirty stocks. Five quarters of Appaloosa's filings, and what it means to invest against the crowd.
Li Lu's Himalaya Capital: seven stocks, nearly half in Alphabet
The investor Charlie Munger trusted with his family's money holds only a handful of companies. Five quarters of Himalaya's filings and the case for fewer, better investments.
Michael Burry's Scion: the big short, a book of options and a fund that stopped reporting
The investor made famous by The Big Short filed his last public stock report for September 2025. What the last five reports show, and why options in a 13F are easy to misread.
Dan Loeb's Third Point: an activist whose reported portfolio shrank by two thirds in one quarter
A hedge fund known for public campaigns against company managers. Five quarters of Third Point's filings show a sharp change in March 2026 that the filing itself does not explain.
Cathie Wood's ARK: disruptive innovation, 190 stocks and Tesla at the top
The best-known growth investor of the 2020s holds nearly two hundred companies in her ETFs. Five quarters of ARK's filings and the idea that cost curves drive technology.
George Soros's fund: reflexivity, big macro bets and a portfolio of 258 positions
The investor who 'broke the Bank of England' explained why prices and beliefs feed each other. Five quarters of the Soros Fund Management filings, with a lot of options.
Ideas that shaped investing
Benjamin Graham: Mr. Market, the margin of safety and the birth of value investing
The teacher of Warren Buffett wrote the two books that turned stock picking into a discipline. What he actually taught, where it holds up, and how six current portfolios compare with his rules.
John Maynard Keynes: the beauty contest, animal spirits and an economist who became an investor
The most famous economist of the twentieth century also managed money, failed at timing the market and then changed his method. His ideas about crowds and concentration, set against six real portfolios.
Harry Markowitz: why diversification is the only free lunch, and how many stocks you really hold
A 1952 paper turned 'do not put all your eggs in one basket' into mathematics. What Markowitz proved, what he left out, and how concentrated six famous portfolios really are.
William Sharpe and John Bogle: the arithmetic of costs and the case for index funds
Two men made the argument that most investors are better off owning the whole market at a low cost. The logic, its limits, and how much of six famous portfolios is in index funds.
Nassim Taleb: black swans, fat tails and the barbell strategy
A former options trader who argues that rare events matter more than averages. His idea of the barbell, why it is hard to see in a filing, and what the six portfolios reveal about risk.
Eugene Fama: efficient markets, factors and why our site is a public experiment
Fama argued that prices already contain all information, then found the exceptions himself. The idea, the factors, the critics, and how a live public scoreboard of sixty bots tests it.
Daniel Kahneman and Richard Thaler: behavioural finance and why rules protect us from ourselves
A psychologist and an economist who showed that people are not the calm calculators the old theory assumed. Loss aversion, mental accounts, nudges, and why a bot with fixed rules does not panic.
Howard Marks: market cycles, risk as the chance of loss and second-level thinking
The co-founder of Oaktree Capital is known for memos that investors read around the world. His view of risk, of cycles and the pendulum of mood, and what it means for a patient investor.