Aquamarine Zurich (Guy Spier) reported 7 equity positions with a combined reported value of $135.3M in its Q1 2026 Form 13F filing. The ten largest of those positions account for 100.0%of the filing’s reported value.
Most recent period on file: 31 Mar 2026 (Q1 2026) · 8 quarters on file · 13F is due 45 days after quarter end
Reported value
$135.3M
13F positions, Q1 2026
Positions
7
Distinct holdings in the filing
Top 10 share
100.0%
Highly concentrated
Quarters on file
8
Through Q1 2026
Ten largest reported positions
Top 7 of 7 positions by reported value · Q1 2026
Ten largest reported positions held by Aquamarine Zurich (Guy Spier) as of 31 Mar 2026
#
Security
CUSIP
Class
Reported value
Shares
Weight
1
BERKSHIRE HATHAWAY INC DEL
084670702
CL B NEW
$46.8M
98K
34.57%
2
BERKSHIRE HATHAWAY INC DEL
084670108
CL A
$21.5M
30
15.92%
3
MASTERCARD INCORPORATED
57636Q104
CL A
$20.0M
40K
14.77%
4
AMERICAN EXPRESS CO
025816109
COM
$19.7M
65K
14.53%
5
MOODYS CORP
615369105
COM
$11.8M
27K
8.71%
6
FERRARI N V
N3167Y103
COM
$10.0M
30K
7.40%
7
DAILY JOURNAL CORP
233912104
COM
$5.5M
12K
4.10%
The full 7-position filing, quarter-over-quarter position changes, concentration analysis and cross-fund security search are in the Fund Tracker dashboard.
Rock Group holds Aquamarine Zurich (Guy Spier)’s 13F filings for Q1 2026, Q4 2025, Q3 2025, Q2 2025, Q1 2025, Q4 2024, Q3 2024, Q2 2024. Period-over-period comparison — positions added, exited and resized — is available in the dashboard.