Aquamarine Capital 13F, Q4 2025
Guy Spier · quarter ending 31 December 2025 · filed 15 January 2026 · SEC CIK 1953324
Common stock only: shares the fund reported owning at the quarter end, valued as filed.
Largest positions, Q4 2025
Weights are against the whole filed book. Changes are in shares held, against the Q3 2025 filing.
| Company | Ticker | Value | % of book | vs Q3 2025 |
|---|---|---|---|---|
| BERKSHIRE HATHAWAY INC DEL | BRK/B | $49.06M | 33.3% | -31% shares |
| AMERICAN EXPRESS CO | AXP | $24.05M | 16.3% | -69% shares |
| MASTERCARD INCORPORATED | MA | $22.84M | 15.5% | -39% shares |
| BERKSHIRE HATHAWAY INC DEL | BRK/A | $22.64M | 15.3% | unchanged |
| MOODYS CORP | MCO | $13.79M | 9.3% | unchanged |
| FERRARI N V | $9.56M | 6.5% | -50% shares | |
| DAILY JOURNAL CORP | DJCO | $5.60M | 3.8% | unchanged |
What changed since Q3 2025
Against the Q3 2025 filing, Aquamarine Capital opened 0 new positions, added to 0, trimmed 4, left 3 unchanged and exited 7. Every position is compared, matched on its CUSIP; a change of 2% or less in shares counts as unchanged.
Other quarters
Source: SEC Form 13F-HR, accession 0001953324-26-000001, filed by Aquamarine Zurich AG. Values are as filed and cover US-listed positions only; a 13F does not show short positions or holdings outside the US. A 13F may be filed up to 45 days after the quarter ends, so the fund may have traded since. Educational information, not financial advice.