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Guy Spier: Concentrated Value Investing Remains Core Strategy

Wednesday, March 4, 2026 · Johnny Hopkins

Guy Spier’s Aquamarine Zurich AG reported an equity portfolio of approximately $148 million in the latest quarter, maintaining its hallmark concentrated, Buffett-inspired long-term investment approach. The portfolio is highly focused, with the top holdings representing virtually the entire portfolio, reflecting Spier’s preference for owning a small number of high-quality compounders held over long time horizons.

The latest filing shows meaningful trims in several core financial holdings and a full exit from a number of prior positions, suggesting portfolio simplification and further concentration into highest-conviction names.

Aquamarine continues to emphasize durable franchises, strong management, and businesses with long-term pricing power — consistent with Spier’s value investing philosophy.


Portfolio Snapshot

Total Portfolio Value: ~$147.5M
Top 10 Weight: 100% (extremely concentrated)
Turnover: Moderate — notable trims and multiple full exits


Top Holdings & Weights

Company Ticker Value Portfolio %
Berkshire Hathaway (Class B) BRK.B ~$49.1M ~33.3%
American Express AXP ~$24.0M ~16.3%
Mastercard MA ~$22.8M ~15.5%
Berkshire Hathaway (Class A) BRK.A ~$22.6M ~15.3%
Moody’s MCO ~$13.8M ~9.4%
Ferrari RACE ~$9.6M ~6.5%
Daily Journal Corp DJCO ~$5.6M ~3.8%

Key takeaway:
The portfolio heavily emphasizes:

  • Berkshire Hathaway (combined exposure nearly 49%)

  • High-quality financial franchises (AXP, MA, MCO)

  • Select global luxury/brand assets (Ferrari)

  • A legacy value holding (Daily Journal)

This reflects Spier’s long-standing admiration for Buffett-style capital allocation and wide-moat businesses.


Biggest Changes Last Quarter

Notable Trims

American Express (AXP):
Shares reduced materially (~-69%)
→ Significant position reduction while remaining a core holding.

Mastercard (MA):
Trimmed (~-39%)
→ Suggests partial profit-taking or capital reallocation.

Berkshire Hathaway (BRK.B):
Reduced (~-31%)
→ Likely position management while maintaining Berkshire as the dominant exposure.

Ferrari (RACE):
Trimmed (~-50%)
→ Substantial reduction in luxury exposure.


Full Exits Last Quarter

Aquamarine exited several prior holdings entirely:

  • Bank of America (BAC)

  • Micron Technology (MU)

  • Alibaba (BABA)

  • Alphabet (GOOGL)

  • Seritage Growth Properties (SRG)

  • Alpha Metallurgical Resources (AMR)

  • Core Natural Resources (CNR)

These exits suggest continued portfolio simplification and a move away from cyclical, commodity-linked, and certain technology exposures in favor of ultra-high-conviction compounders.


Portfolio Characteristics

Style: Concentrated Quality Value
Concentration: Extremely high (top holdings dominate portfolio)
Turnover: Opportunistic trimming with decisive exits

Core Themes:

  • Berkshire-centric exposure

  • Financial services and payments networks

  • Rating agencies and durable franchises

  • Select premium global brands

Geographic Exposure:

  • Predominantly U.S.-listed companies

  • Limited but high-quality international exposure (Ferrari)


Summary

Guy Spier’s latest filing reinforces his disciplined, concentrated approach to investing. The portfolio remains heavily anchored in Berkshire Hathaway and a handful of high-quality financial franchises, reflecting a philosophy centered on long-term compounding rather than diversification.

The quarter saw meaningful trimming across several major holdings and the full exit of multiple smaller positions, indicating portfolio simplification and renewed focus on highest-conviction businesses.

Overall, Aquamarine’s structure continues to mirror Spier’s Buffett-inspired strategy: own exceptional businesses, maintain patience, and allow intrinsic value to compound over time.

Guy Spier: Concentrated Value Investing Remains Core Strategy · The Acquirer's Multiple®