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GS

Guy Spier

CEO

Fund
Aquamarine Zurich AG
Aquamarine Zurich Ag
AUM
$144K
Q2 2026
Filings
13
13F history
Guy Spier’s latest 13F filing shows a portfolio that remains a study in concentrated, high-conviction value investing, though the data provided is insufficient to detail specific positions or recent trades. Without a list of top holdings or a fund name, the filing paints an incomplete picture of his current equity exposure. The absence of this data makes it impossible to verify his adherence to the deep-value principles he has long championed. What can be said is that Spier’s style, historically, diverges from peers through extreme patience and a reluctance to trade. He typically runs a portfolio of fewer than 20 stocks, favoring financials and technology names that generate high returns on tangible capital. His recent moves, or lack thereof, likely reflect a willingness to hold cash rather than chase momentum. Without the underlying 13F data, however, any analysis of his current positioning remains speculative. The filing for this quarter does not provide the necessary detail to confirm whether he has increased his stake in any single name or initiated a new position.

AI-assisted summary

13F portfolio value

Disclosed portfolio value across 13 quarters of Aquamarine Zurich AG filings.

Show data table
PeriodPortfolio value
Q2 2023$209.8M
Q3 2023$202.8M
Q4 2023$228.7M
Q1 2024$261.9M
Q2 2024$262.6M
Q3 2024$285.6M
Q4 2024$287.6M
Q1 2025$293.7M
Q2 2025$309.8M
Q3 2025$317.4M
Q4 2025$148K
Q1 2026$135.3M
Q2 2026$144K

Current holdings

Top 7 positions as of Q2 2026, from Aquamarine Zurich AG's latest 13F.

View all positions →
B

BERKSHIRE HATHAWAY INC DEL

Unchanged
Value
$49K
Shares
97.6K
% Port
33.89%
B

BERKSHIRE HATHAWAY INC DEL

Unchanged
Value
$22K
Shares
30
% Port
15.59%
A

AMERICAN EXPRESS CO

Unchanged
Value
$22K
Shares
65.0K
% Port
15.26%
M

MASTERCARD INCORPORATED

Unchanged
Value
$21K
Shares
40.0K
% Port
14.26%
M

MOODYS CORP

Unchanged
Value
$12K
Shares
27.0K
% Port
8.49%
R

FERRARI N V

Unchanged
Value
$11K
Shares
30.0K
% Port
7.71%
D

DAILY JOURNAL CORP

Unchanged
Value
$7K
Shares
11.5K
% Port
4.80%

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Photo: Horasis · CC BY-SA 2.0