Aquamarine Capital (Aquamarine Zurich)
In its 13F for Q3 2025 (holdings as of September 30, 2025, filed October 20, 2025), Guy Spier's Aquamarine Capital (Aquamarine Zurich) reported 14 stock positions worth $317.4 million. Its top holding was Berkshire Hathaway Class B (BRK.B) at 22.3% of the portfolio, followed by American Express (AXP, 22.0%) and Bank of America (BAC, 12.5%). Compared with Q2 2025, it reduced 1. The biggest sale was Micron Technology (MU, shares −60%).
- Most Recent 13F
- Q2 2026
- Notable People
- Guy Spier
- Location
- ZURICH, V8
- CIK
- 0001953324
- Portfolio Value
- $317.4M (Q3 2025)
- SEC Filing
- 0001953324-25-000007 ↗ filed Oct 20, 2025
Holdings Value
Holdings 14 stocks · $317.4M
| BRK.B Berkshire Hathaway Inc. Class B | 22.27% | 140,600 | $70.7M | No change |
| AXP American Express Co. | 21.98% | 210,000 | $69.8M | No change |
| BAC Bank of America Corp. filed as BANK AMERICA CORP | 12.48% | 767,845 | $39.6M | No change |
| MA Mastercard Inc. Class A | 11.78% | 65,750 | $37.4M | No change |
| RACE Ferrari NV | 9.13% | 60,000 | $29.0M | No change |
| BRK.A Berkshire Hathaway Inc. Class A | 7.13% | 30 | $22.6M | No change |
| MU Micron Technology Inc. | 4.22% | 80,000 | $13.4M | Reduce -60.0% |
| MCO Moody's Corp. | 4.05% | 27,000 | $12.9M | No change |
| BABA Alibaba Group Holding-SP ADR | 2.68% | 47,500 | $8.5M | No change |
| DJCO Daily Journal Corp. | 1.69% | 11,500 | $5.3M | No change |
| GOOGL Alphabet Inc. Class A | 1.23% | 16,000 | $3.9M | No change |
| SRG Seritage Growth Prop- A | 0.67% | 500,000 | $2.1M | No change |
| AMR Alpha Metallurgical Resource | 0.41% | 8,000 | $1.3M | No change |
| CNR Core Natural Resources Inc. | 0.28% | 10,740 | $897K | No change |
Portfolio Sells Q2 2025 → Q3 2025
| MU Micron Technology Inc. | Reduce -60.0% | 4.22% | −3.74 |
Portfolio Buys Q2 2025 → Q3 2025
| None this quarter. | |||
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 7 | $144.1M | BRK.B, BRK.A, AXP, MA, MCO |
| Q1 2026 | 7 | $135.3M | BRK.B, BRK.A, MA, AXP, MCO |
| Q4 2025 | 7 | $147.5M | BRK.B, AXP, MA, BRK.A, MCO |
| Q3 2025 | 14 | $317.4M | BRK.B, AXP, BAC, MA, RACE |
| Q2 2025Amended | 14 | $309.8M | BRK.B, AXP, MA, BAC, RACE |
| Q1 2025Amended | 14 | $293.7M | BRK.B, AXP, MA, BAC, BRK.A |
| Q4 2024 | 14 | $287.6M | BRK.B, AXP, MA, BAC, RACE |
| Q3 2024 | 14 | $285.6M | BRK.B, AXP, MA, BAC, RACE |
| Q2 2024 | 14 | $262.6M | BRK.B, AXP, BAC, MA, MU |
| Q1 2024 | 12 | $261.9M | BRK.B, AXP, MA, BAC, RACE |