Guy Spier’s Aquamarine Capital Q3 2026 13F Portfolio Analysis: The Power of Absolute Inactivity

The Form 13F quarterly report submitted by Aquamarine Capital—filed under the corporate entity Aquamarine Zurich AG for the period ended September 30, 2026, and accepted by the U.S. Securities and Exchange Commission on November 10, 2026—presents a masterclass in institutional patience: absolute portfolio inactivity. Throughout the third quarter of 2026, manager Guy Spier executed zero new position entries, zero share additions to existing positions, zero position trims, and zero complete liquidations across his U.S. long equity portfolio. Operating with an estimated quarterly turnover of 0.0% and balancing buys and sells at exactly ~$0 based on quarter-end prices, Aquamarine Capital held its reported U.S. equity footprint static at $144.3 million across 7 positions, compared to $144.1 million across the exact same 7 holdings in Q2 2026. For value-oriented market participants, this complete absence of transaction activity is far from a passive oversight; it represents a deliberate, high-conviction application of classic value investing theory, demonstrating how extreme patience and high hurdles for capital reallocation dictate portfolio strategy during shifting market environments.

The investor: philosophy, fund and lifetime work#

Aquamarine Capital is categorized by DeepValues Research under the traditional value investing framework, adhering strictly to fundamental, bottom-up business evaluation and long-term owner-oriented capital allocation. The manager submits regulatory disclosures to the SEC under the institutional filer name Aquamarine Zurich AG (Central Index Key / CIK: 0001953324), maintaining its principal mailing and business address at Ramistrasse 18, Zurich, Switzerland (V8 8001; business contact telephone 0041-44-210-19-00). The firm's SEC Form 13F-HR for the quarterly reporting period ending September 30, 2026 (Accession Number: 0001953324-26-000004, Commission File Number: 028-22669, Film Number: 261538581) was transmitted and accepted on November 10, 2026.

Spier is an established figure within the global value investment community, known for his written works, digital media, and institutional stewardship. He authored the investment memoir The Education of a Value Investor, published on September 9, 2014, by Palgrave MacMillan (ISBN 978-1137278814). In addition to his book, Spier shares insights via his personal website (www.guyspier.com, redirected via go.aqu.am/guyspier) and hosts a podcast broadcast on his YouTube channel, also titled The Education of a Value Investor, which has accumulated 13 thousand subscribers and over 454 thousand aggregate video views.

Biographical Trajectory & Academic Background#

Guy Selmar Spier was born on February 4, 1966, in Pietermaritzburg, South Africa. His early childhood involved extensive international relocations across three continents: * Tel Aviv, Israel: When Spier was three months old, his family moved to Tel Aviv, where he spent his early years and attended kindergarten. * Tehran, Iran: In 1970, his family relocated to Tehran, Iran, where Spier attended the British Embassy School. * Richmond & Ashtead, United Kingdom: In 1977, the family moved to Richmond in the United Kingdom. Spier completed his secondary education at the City of London Freemen's School in Ashtead, Surrey, attending as a weekly boarder.

Spier’s higher education spans major academic institutions in the United Kingdom, the United States, and Germany. In 1984, he matriculated at Brasenose College, Oxford, initially reading law. In 1986, he transitioned his area of study to Politics, Philosophy and Economics (PPE). Following his undergraduate education at Oxford, Spier pursued post-graduate studies at Harvard Business School and also studied at Heidelberg University in Germany.

Professional Career & Key Institutional Milestones#

Spier began his career in strategic management consulting before shifting into investment management: * Braxton Associates: From 1988 to 1990, Spier worked as an associate at Braxton Associates, a strategy consulting firm that was later acquired by Deloitte Consulting. * Aquamarine Fund: Following a period in investment banking, Spier departed the sector to establish the Aquamarine Fund, creating a investment vehicle modeled after the classic investment partnerships of the 1950s and 1960s. * 2003 Short-Sale Regulatory Scrutiny: In 2003, Spier—alongside hedge fund managers David Einhorn, Bill Ackman, and Whitney Tilson—became subject to regulatory investigations spearheaded by Eliot Spitzer (then Attorney General of New York) and the U.S. Securities and Exchange Commission. The investigations targeted their public short-sale theses against financial entities including Farmer Mac, MBIA, and Allied Capital. The thesis was ultimately vindicated during the 2008 global financial crisis, highlighted by credit rating events such as Moody's two-notch downgrade of MBIA in June 2008. * 2016 Delaware Bankruptcy Court Petition: In 2016, Spier partnered with investors Phil Town and Matthew Peterson to petition Judge Sontchi in the U.S. Bankruptcy Court for the District of Delaware. Their legal intervention successfully established an official committee of equity holders for Horsehead Holding Corporation following its Chapter 11 bankruptcy filing earlier that year.

Spier resides in Zurich, Switzerland, with his wife Lory (whom he married in 2003) and their three children.

The portfolio at quarter end: size, concentration, core holdings#

As of September 30, 2026, Aquamarine Capital’s U.S. long equity holdings totaled $144.3 million in market value across 7 reported positions. This represents a minor expansion in aggregate portfolio value from the $144.1 million reported in Q2 2026 across the identical set of 7 securities, driven entirely by underlying market price changes rather than trading activity.

The portfolio is defined by extreme asset concentration. The top 7 positions account for exactly 100.0% of the firm's total reported U.S. long equity assets.

Aquamarine Capital Q3 2026 U.S. Long Equity Portfolio#

Position-by-Position Portfolio Breakdown#

• Berkshire Hathaway Inc. Class B (BRK.B): Retaining its status as Aquamarine's largest single position, Class B shares accounted for $48.6 million, representing 33.7% of reported U.S. equity assets. The share count remained completely unchanged during the quarter.
• Berkshire Hathaway Inc. Class A (BRK.A): The fund’s second-largest allocation is Berkshire's Class A common stock, valued at $22.4 million and representing 15.5% of the portfolio. The share count remained unchanged from Q2 to Q3 2026.
• Mastercard Incorporated (MA): Occupying the third rank, payment processing giant Mastercard represents $22.1 million, or 15.3% of aggregate U.S. long equity assets. Spier executed zero trades in Mastercard shares during the period.
• American Express Co (AXP): Ranked fourth, financial services platform American Express stands at $19.8 million, constituting 13.7% of reported holdings, with share counts remaining static.
• Moody's Corporation (MCO): Credit rating and financial analytics provider Moody's ranks fifth, comprising $12.3 million or 8.5% of total portfolio value, maintaining an unchanged position size.
• Ferrari N.V. (RACE): Italian luxury automotive manufacturer Ferrari represents the sixth largest holding at $11.8 million, accounting for 8.2% of the U.S. long portfolio with zero share count modifications.
• Daily Journal Corporation (DJCO): Niche legal publishing and software enterprise Daily Journal represents the seventh position, valued at $7.4 million, or 5.1% of reported U.S. equity assets, holding firm without trading activity.

Portfolio Concentration Analysis#

An analytical examination of Aquamarine Capital's Q3 2026 filing reveals extreme structural concentration: 1. Berkshire Hathaway Dominance: When combining Class B (BRK.B at $48.6 million) and Class A (BRK.A at $22.4 million) shares, total exposure to Berkshire Hathaway equals $71.0 million. This dual-class allocation represents 49.2% of Aquamarine’s aggregate reported U.S. equity portfolio, effectively anchoring nearly half of the fund's long U.S. equity footprint to Warren Buffett's conglomerate vehicle. 2. Capital-Light Financial Networks & Toll-Booth Moats: The secondary pillar of the portfolio consists of high-margin, capital-light payment networks and financial services. Mastercard (MA at 15.3%) and American Express (AXP at 13.7%) collectively account for 29.0% of reported capital. When combined with credit rating agency Moody's (MCO at 8.5%), financial processing and rating moats comprise 37.5% of total assets. 3. Specialized Brands & Niche Operations: The final 13.3% of the portfolio is divided between global luxury automotive franchise Ferrari N.V. (RACE at 8.2%) and specialized regional enterprise Daily Journal Corporation (DJCO at 5.1%).

What changed: new, added, trimmed and sold-out positions#

During the third quarter of 2026, Aquamarine Capital demonstrated absolute portfolio stability across its U.S. equity holdings: * New Positions: 0 * Added Positions: 0 * Trimmed Positions: 0 * Sold-Out Positions: 0

Turnover & Estimated Cash Flows#

Based on prevailing quarter-end valuation prices, estimated portfolio purchases totaled ~$0 and estimated portfolio sales totaled ~$0. Consequently, portfolio turnover for the third quarter of 2026 was approximately 0.0%, reflecting absolute capital equilibrium.

Managerial Motive Analysis#

Inference: Spier's decision to maintain zero trading activity in Q3 2026 aligns directly with the "do-nothing" investment framework famously advocated by Warren Buffett and Charlie Munger. Under this methodology, portfolio turnover is viewed not as a metric of diligence, but as a potential drag on long-term compounding due to frictional tax liabilities and transaction costs. By maintaining static positions across Berkshire Hathaway, Mastercard, American Express, Moody's, Ferrari, and Daily Journal, Spier signals that his hurdle rate for capital reallocation remains unfulfilled. Rather than adjusting positions in response to quarter-to-quarter macroeconomic commentary, Spier chooses to let established compounders reallocate capital internally, holding cash or core equity positions intact until clear price-to-value discrepancies manifest in prospective target businesses.

The biggest moves, valued#

Valuation Limitation Requirement#

No valuation worksheet could be constructed for Aquamarine Capital’s top portfolio holdings for the Q3 2026 reporting period. Under the DeepValues Research institutional methodology, financial service companies, bank holding entities, investment funds, and the majority of foreign-domiciled filers are excluded from standardized discounted cash flow (DCF) and owner earnings valuation models.

Valuation Transparency Statement#

Because structural exclusions apply across Aquamarine’s reported holdings—which consist of financial institutions (American Express), credit rating services (Moody's Corporation), diversified holding companies (Berkshire Hathaway), transaction processors (Mastercard), foreign-domiciled entities (Ferrari N.V.), and specialized publishing/software vendors (Daily Journal Corporation)—standard intrinsic value calculations were omitted. Consequently, no intrinsic value estimates, owner earnings ranges, or margins of safety are provided for Berkshire Hathaway (BRK.A / BRK.B), Mastercard (MA), American Express (AXP), Moody's Corporation (MCO), Ferrari N.V. (RACE), or Daily Journal Corporation (DJCO).

Track record: the ten-year 13F clone against the S&P 500#

To measure the historical efficacy of Aquamarine Capital’s public U.S. long disclosures, DeepValues Research tracks a standardized 10-year "13F Clone" model performance benchmark.

13F Clone Methodology Parameters#

The 13F Clone methodology simulates the return profile of a public market investor systematically replicating Aquamarine Capital’s SEC filings: * Execution Protocol: Each quarterly Form 13F filing's U.S. common stock positions, weighted by their reported market value, are purchased at the market close on the first trading day immediately following the official SEC EDGAR filing date (the exact window when public disclosure occurs). * Rebalancing Cadence: Positions are held static until the public release of the subsequent quarter’s 13F filing, at which point the clone portfolio is rebalanced to match the updated dollar-weighted position allocations. * Price Adjustment & Benchmark: Returns utilize dividend-adjusted share prices and are benchmarked directly against the total return of the S&P 500 ETF (SPY). * Evaluation Window: November 10, 2016, through November 10, 2026 (spanning 10.0 calendar years and 24 quarterly filing cycles).

10-Year Performance Summary (2016–2026)#

Over the 10-year tracking window, the Aquamarine 13F Clone generated substantial long-term capital appreciation that closely mirrored the broader U.S. equity market: * Aquamarine 13F Clone: Compound Annual Growth Rate (CAGR) of 14.8%, Cumulative Total Return of +296.0%, and a Maximum Drawdown of -28.2% (calculated on a month-end basis). * S&P 500 Total Return (SPY): Compound Annual Growth Rate (CAGR) of 15.0%, Cumulative Total Return of +304.5%, and a Maximum Drawdown of -23.9%. * Annualized Performance Differential: -0.2 percentage points per year relative to the benchmark index. * Best Relative Calendar Year: 2017 (+37.0% clone return vs. +21.7% SPY total return; generating +15.3 percentage points of alpha). * Worst Relative Calendar Year: 2020 (+2.1% clone return vs. +18.3% SPY total return; lagging the benchmark by -16.2 percentage points). * Down-Market Relative Performance: In 2022, during a broad market retrenchment, the 13F Clone declined by -11.8% compared to SPY’s decline of -18.2%, generating +6.4 percentage points of relative outperformance.

Year-by-Year Performance Comparison Table (2016–2026)#

* Note: Indicates partial calendar year evaluation window (2016 begins Nov 10, 2016; 2026 ends Nov 10, 2026).

Structural Characteristics & Data Notes#

• Average Holdings Count: The clone portfolio maintained an average of 13 U.S. common stock positions across the 10-year tracking period.
• Top 10 Concentration: The top 10 positions accounted for an average of 96.5% of total reported portfolio value.
• Quarterly Turnover Rate: Historical portfolio turnover averaged ~8.0% per quarter over the decade.
• Historical Reference Point: In the 13F filing dated June 30, 2022, Aquamarine reported $170 million in aggregate value across 12 U.S. common stock holdings.
• Price Coverage Metric: Market price data was successfully retrieved for an average of 88.9% of total reported portfolio value across historical filings. Positions lacking verifiable public market price data were dropped from the calculation, and the remaining assets were proportionally reweighted.
• EDGAR Filing Data Note: The SEC Form 13F filing for the period ending June 30, 2026, was missing from the SEC EDGAR database. To maintain portfolio continuity, the portfolio structure reported in the June 30, 2022 filing was carried forward through the conclusion of the evaluation window on November 10, 2026.

Core 13F Clone Limitations & Disclaimers#

Investors analyzing public 13F tracking data must recognize fundamental structural limitations: 1. Fund Net Return Disconnect: The 13F Clone return does not reflect the actual net return of the Aquamarine Capital fund or its underlying investors, as fund expenses, management fees, and performance allocations are excluded. 2. Omission of Non-U.S. & Alternative Assets: The clone framework exclusively tracks U.S.-listed long equity securities. It completely omits cash reserves, short positions, fixed-income bonds, foreign equities listed on international exchanges, and options contracts. 3. Regulatory Reporting Delay: Disclosures are submitted up to 45 days following the conclusion of each quarter, introducing a structural lag between managerial execution and public visibility. 4. Intra-Quarter Trading Blind Spot: Any investment positions acquired and completely liquidated within a single calendar quarter are absent from SEC Form 13F disclosures.

What a patient investor can learn#

Aquamarine Capital’s Q3 2026 13F disclosure provides several structural insights for disciplined capital allocators:

1. Absolute Inactivity as an Active Allocation Strategy#

In modern portfolio management, activity is often confused with progress. Guy Spier’s 0.0% quarterly turnover emphasizes that deliberate inactivity is an active allocation choice. When core capital is deployed into dominant financial moats—such as Berkshire Hathaway, Mastercard, and American Express—holding positions unchanged avoids capital gains friction, reduces trading expenses, and prevents reinvestment risk associated with replacing high-quality businesses with inferior alternatives.

2. High-Conviction Allocation Over Broad Diversification#

Aquamarine’s U.S. equity portfolio demonstrates extreme concentration, placing 49.2% of reported capital in a single enterprise (Berkshire Hathaway across Class A and Class B shares) and 100.0% across just 7 businesses. This structural layout illustrates a core value premise: deep fundamental conviction in superior businesses with high economic moats supersedes broad capital diversification across average business models.

3. Discerning Regulatory Disclosure Boundaries#

Institutional 13F analysis requires a clear understanding of regulatory limits. A Form 13F offers a partial window restricted to U.S.-listed long equities. Investors seeking to replicate institutional managers must acknowledge that non-U.S. listings, cash balances, fixed income securities, and derivative hedges remain completely undisclosed in 13F filings, requiring analytical caution when evaluating 13F data.

Key numbers#

• Reported U.S. Long Equity Value (Q3 2026): $144.3 million (vs. $144.1 million in Q2 2026).
• Total Reported U.S. Equity Holdings: 7 positions.
• Top 10 Concentration: 100.0% of reported U.S. equity value.
• Largest Individual Allocations:
  • Berkshire Hathaway Inc. (BRK.B + BRK.A combined): 49.2% ($71.0M aggregate value)
  • Mastercard Incorporated (MA): 15.3% ($22.1M)
  • American Express Co (AXP): 13.7% ($19.8M)
• Q3 2026 Trading Activity: 0 buys, 0 sells (~0.0% quarterly turnover).
• 10-Year 13F Clone Track Record (2016–2026):
  • Aquamarine 13F Clone: 14.8% CAGR (+296.0% total return; max drawdown -28.2%).
  • S&P 500 Index (SPY): 15.0% CAGR (+304.5% total return; max drawdown -23.9%).
  • Annualized Performance Differential: -0.2 percentage points per year.

Closing Note on 13F Limits & Legal Disclaimer#

Structural Limits of SEC Form 13F Filings#

Form 13F filings provide an incomplete snapshot of institutional investment portfolios: * Reporting Lags: Under SEC regulations, Form 13F filings are submitted up to 45 days after the end of each calendar quarter. The information presented herein reflects portfolio holdings as of September 30, 2026, and does not capture trades executed after that date. * Omission of Asset Classes: SEC Form 13F mandates disclosure of U.S.-listed long equity holdings only. It explicitly excludes cash reserves, short positions, foreign equity securities listed on non-U.S. exchanges, fixed income securities, commodities, currencies, and options contracts.

Research Disclaimer#

This portfolio analysis is published by DeepValues Research strictly for educational, informational, and analytical purposes. This document does not constitute personalized investment advice, financial analysis, a security recommendation, or an offer to buy or sell securities. Investors must perform independent due diligence and consult certified financial advisors prior to executing capital allocation strategies.