Superinvestors: What Buffett, Dalio & Ackman Are Buying

The Signal

In 1984, Warren Buffett gave a speech at Columbia Business School titled "The Superinvestors of Graham-and-Doddsville." In it, he identified a group of investors — all alumni of Benjamin Graham's value investing school — who had compiled extraordinary long-term records of outperformance. Buffett's central argument was that these results could not be explained by luck. If you assembled 225 million coin-flippers and asked them to flip a coin every year, some would flip heads twenty consecutive times by random chance. But if all the winners came from the same village — Graham-and-Doddsville — you would correctly infer that something in their shared philosophy explained the outcome.

Superinvestor tracking takes Buffett's insight as its starting point. The goal is not to follow every manager filing a 13F, but to identify the handful of investors — perhaps 20–50 in any given era — whose track records are long enough and consistent enough that their disclosed positions carry information value. These are investors like Warren Buffett, whose Berkshire Hathaway has one of the longest documented track records in modern investing; Seth Klarman, whose Baupost Group is known for a value discipline built around downside protection; Bill Ackman, whose concentrated activist approach at Pershing Square takes large stakes in a small number of names; and a handful of other managers with similarly long, publicly verifiable records.

What makes these investors special is not just their returns but their process. Superinvestors typically share a set of characteristics: they hold concentrated portfolios of 5–20 positions rather than diversified collections of hundreds; they have multi-year investment horizons measured in years rather than months; they publish detailed letters explaining their reasoning; and they stake significant personal capital in their investments. This combination of concentration, patience, transparency, and skin-in-the-game makes their public disclosures among the most informative available in any market.

Why the Approach Has a Rationale

The case for superinvestor tracking rests on the same 13F disclosure regime that underpins institutional tracking generally — but the "superinvestor" framing focuses on a pre-selected, high-quality subset of managers rather than the average institutional investor. The logic is one of information, not of a guaranteed return: managers with long, publicly verifiable records are, by construction, the fraction that has persisted over time, and their largest disclosed positions reflect where they have concentrated capital.

Academic work on portfolio cloning explores whether an investor can replicate the disclosed holdings of skilled managers. Schroeder and Posch (2024) study clone portfolios built from SEC Form 13F filings and find that top-quartile clones can track the underlying funds closely; their results are from a working paper covering 2013–2023 and should be read as descriptive of a method, not as a promise of forward returns. Cloning is appealing in principle because it captures a manager's disclosed research output without paying the manager's fees — though the 45-day filing lag and turnover mean a clone is never a perfect copy.

Verbeek and Wang (2013) examine "copycat" funds that duplicate mutual-fund disclosures. Their finding is measured: after accounting for transaction costs and expenses, copycat portfolios tend to perform comparably to their targets, with their relative success improving after 2004 when the SEC required quarterly disclosure. The takeaway is that cloning can capture much of a manager's research value at lower cost — not that a clone reliably beats the original.

The Cohen, Polk, and Silli "Best Ideas" working paper reinforces why focusing on a manager's top positions is worthwhile. Their research found that fund managers' single highest-conviction positions historically outperformed both the market and the rest of those managers' portfolios, while the majority of other holdings did not. That is a reason to weight a manager's largest, most-concentrated bets more heavily than the long tail of small positions. Buffett's largest holdings, Ackman's concentrated stakes, Klarman's special-situation bets: these are positions built on deep research, not diversification mandates.

Multi-manager overlap adds a further filter. When two or more independent superinvestors hold the same position, the case that it reflects a genuine fundamental view — rather than passive exposure or idiosyncrasy — is stronger than for any single manager alone. Overlap does not guarantee the thesis is correct, but it does concentrate attention on names that multiple independent research processes have converged on.

What the Data Surfaces

• Portfolio cloning research (Schroeder & Posch, 2024, working paper) studies whether top-quartile clones built from 13F filings can track the underlying funds — a method-level result, not a forward-return promise
• Buffett's Berkshire Hathaway has one of the longest documented track records in modern investing, spanning more than five decades
• Seth Klarman's Baupost Group is associated with a value discipline centered on downside protection and patient, multi-year holding
• Copycat-fund research (Verbeek & Wang, 2013) finds cloned portfolios can perform comparably to their targets after costs — capturing research value without the manager's fees
• Multi-manager overlap (the same name held by two or more superinvestors) is used as a higher-conviction filter because it reflects multiple independent research processes converging
• The "Best Ideas" effect (Cohen, Polk & Silli) suggests a manager's single highest-conviction position historically carried more information than the rest of the book
• Platforms like Dataroma and GuruFocus track dozens of superinvestors, updating each quarter after 13F filings
• Superinvestor portfolios tend to be concentrated — often a few dozen positions or fewer, with the top holdings representing a large share of the portfolio
• Ackman's Pershing Square runs a concentrated book of roughly 6–10 core positions, a structural feature of its activist approach
• The 45-day 13F lag matters less for superinvestors: their multi-year holding periods mean a position disclosed today is often still held quarters later

How Meridian Presents Superinvestor Filings

Meridian organizes delayed public holdings reports so users can compare reported positions, changes, concentration, and filing dates. A large reported holding can be relevant context, but it does not reveal the manager's current view or predict performance. The public product does not assign or disclose a source weight from those observations.

Key Takeaways

• Buffett's 1984 "Superinvestors of Graham-and-Doddsville" article established the framework: a cluster of concentrated, deep-research investors from the same value tradition is unlikely to be explained by chance alone
• Portfolio-cloning research (Schroeder & Posch, 2024, working paper) studies whether 13F-based clones can track skilled managers — a method, not a guaranteed return
• The 45-day 13F disclosure lag is less problematic for superinvestors because their holding periods often span multiple years
• Multi-superinvestor overlap — when several independent investors own the same stock — is used as a higher-conviction filter
• Platforms like Dataroma.com track dozens of superinvestors' disclosed positions, refreshed after each 13F filing
• Weight top positions (by conviction) more heavily than full portfolios — the Best Ideas research suggests information is concentrated at the top of the book
• Superinvestor signals are most useful in combination with other data (for example, short interest or insider activity) rather than in isolation

Expert Perspectives

"If you find three wonderful businesses in your lifetime, you'll be very wealthy. And I've had more than three." — Warren Buffett

Buffett's emphasis on the rarity of truly wonderful businesses explains why tracking his disclosed positions is so valuable — when Berkshire holds something for years, it reflects a deep fundamental conviction developed over years of research and relationship.

"Diversifying well is the most important thing you need to do in order to invest well." — Ray Dalio

Dalio's perspective provides useful balance to concentrated superinvestor cloning. His point is not that concentration is wrong, but that true diversification — across uncorrelated return streams — is what preserves capital over long periods. Superinvestor tracking should be one uncorrelated stream in a broader portfolio, not the entirety of it.

"To be a successful investor, you need to think differently from others, but you also need to be right." — Howard Marks

Marks captures the essential challenge of superinvestor tracking: just because Buffett or Ackman holds a position doesn't guarantee it will work. What it does guarantee is that a sophisticated investor with a 40-year track record has done the research. That's a meaningful signal — but context and valuation still matter.

Further Reading

• Schroeder, J., & Posch, P. (2024). "Outperforming the Market: Portfolio Strategy Cloning from SEC 13F Filings." SSRN Working Paper. Studies whether portfolios cloned from 13F filings can track skilled managers; a working-paper method study, not peer-reviewed.
• Buffett, W. (1984). "The Superinvestors of Graham-and-Doddsville." Hermes, Columbia Business School. Argues the concentration of long-term outperformers in the value investing tradition is too high to be explained by luck alone.
• Verbeek, M., & Wang, Y. (2013). "Better than the Original? The Relative Success of Copycat Funds." Journal of Banking & Finance, 37(9), 3454–3471. Finds copycat portfolios perform comparably to their targets after costs, with success improving after 2004 quarterly-disclosure rules.
• Cohen, L., Polk, C., & Silli, B. (2010). "Best Ideas." SSRN / LSE Working Paper. Finds fund managers' single highest-conviction positions historically outperformed the rest of their portfolios.

Accessing Superinvestor Data

The practical infrastructure for superinvestor tracking has become remarkably accessible over the past decade. Dataroma.com is the canonical free starting point: it tracks approximately 70 superinvestors' 13F-reported positions, providing a searchable interface to see current holdings, recent changes, and the "popularity" of specific stocks across the tracked universe. GuruFocus extends this with deeper historical data, valuation metrics, and alerts when tracked managers make portfolio changes.

For a more quantitative approach, WhaleWisdom allows you to construct custom clone portfolios from any combination of tracked managers, backtest them against historical data, and monitor for new position changes as 13F filings are processed. The platform's "clone portfolio" feature is one of the most direct implementations of the academic research literature on institutional tracking — allowing individual investors to construct and monitor the kind of concentrated, high-conviction portfolio that the Cohen, Polk, and Silli "Best Ideas" research studied. Historical backtests are descriptive of the past and do not guarantee future results.

The key discipline in superinvestor tracking is resisting the temptation to follow every position change. The signal quality is highest in the positions that represent genuine conviction — large holdings that have persisted across multiple quarters, or significant new additions representing a meaningful allocation of the manager's total portfolio. A Buffett position that is 8% of Berkshire's portfolio is worth far more analytical attention than a 0.3% position that may reflect nothing more than a routine cash deployment. Filter for size, filter for persistence, and focus your attention where the concentration of capital signals the concentration of conviction.