Aquamarine Capital (Aquamarine Zurich)
In its 13F for Q4 2025 (holdings as of December 31, 2025, filed January 15, 2026), Guy Spier's Aquamarine Capital (Aquamarine Zurich) reported 7 stock positions worth $147.5 million. Its top holding was Berkshire Hathaway Class B (BRK.B) at 33.3% of the portfolio, followed by American Express (AXP, 16.3%) and Mastercard Class A (MA, 15.5%). Compared with Q3 2025, it sold out of 7 and reduced 4. The biggest sale was an exit from Bank of America (BAC).
- Most Recent 13F
- Q2 2026
- Notable People
- Guy Spier
- Location
- ZURICH, V8
- CIK
- 0001953324
- Portfolio Value
- $147.5M (Q4 2025)
- SEC Filing
- 0001953324-26-000001 ↗ filed Jan 15, 2026
Holdings Value
Holdings 7 stocks · $147.5M
| BRK.B Berkshire Hathaway Inc. Class B | 33.25% | 97,600 | $49.1M | Reduce -30.6% |
| AXP American Express Co. | 16.30% | 65,000 | $24.0M | Reduce -69.0% |
| MA Mastercard Inc. Class A | 15.48% | 40,000 | $22.8M | Reduce -39.2% |
| BRK.A Berkshire Hathaway Inc. Class A | 15.35% | 30 | $22.6M | No change |
| MCO Moody's Corp. | 9.35% | 27,000 | $13.8M | No change |
| RACE Ferrari NV | 6.48% | 30,000 | $9.6M | Reduce -50.0% |
| DJCO Daily Journal Corp. | 3.80% | 11,500 | $5.6M | No change |
Portfolio Sells Q3 2025 → Q4 2025
| BAC Bank of America Corp. | Sold out | 0.00% | −12.48 |
| AXP American Express Co. | Reduce -69.0% | 16.30% | −5.68 |
| MU Micron Technology Inc. | Sold out | 0.00% | −4.22 |
| BABA Alibaba Group Holding-SP ADR | Sold out | 0.00% | −2.68 |
| RACE Ferrari NV | Reduce -50.0% | 6.48% | −2.65 |
| GOOGL Alphabet Inc. Class A | Sold out | 0.00% | −1.23 |
| SRG Seritage Growth Prop- A | Sold out | 0.00% | −0.67 |
| AMR Alpha Metallurgical Resource | Sold out | 0.00% | −0.41 |
| CNR Core Natural Resources Inc. | Sold out | 0.00% | −0.28 |
| MA Mastercard Inc. Class A | Reduce -39.2% | 15.48% | +3.69 |
| BRK.B Berkshire Hathaway Inc. Class B | Reduce -30.6% | 33.25% | +10.98 |
Portfolio Buys Q3 2025 → Q4 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 |