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Built from publicly disclosed institutional and insider activity. Informational purposes only - not investment advice.OpenStocks · v0.1
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  1. Home/
  2. Super Investors/
  3. Guy Spier (Aquamarine Zurich)
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  • Performance8Q
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Guy Spier

Aquamarine Zurich
Share
  • Hedge Fund · CIK 0001953324
  • Financials-Focused
  • Highly Concentrated
  • Boutique

Guy Spier runs Aquamarine Zurich, a hedge fund overseeing $135K in disclosed equity holdings (SEC CIK 0001953324). The latest portfolio (2026Q1) discloses 7 positions across 2 sectors, with the largest positions in BRK.B, BRK.A and MA. On a mark-to-market basis the tracked portfolio has returned 53.6% since 2024Q2. OpenStocks tracks 8 consecutive quarterly snapshots for this manager — every position change, new entry, and exit is logged below.

Track Guy's filingsView holdings↓
Portfolio
$135.3K
Positions
7
Quarter
2026Q1
Filings tracked
8
Since filing+53.6%Full performance →
Quarter
2026Q12025Q42025Q32025Q22025Q12024Q42024Q32024Q2

Holdings

Sorted by value · 2025Q2
14 positions
1
B
BRK.BBERKSHIRE HATHAWAY INC DEL
22.04%
of portfolio
Number of shares
140,600 sh
Holdings current value
$68.30M
Avg closing price
$406.80
+15.7%
Last action
Trimmed 23.4%
2025Q4
Current $470.55
2
A
AXPAMERICAN EXPRESS CO
Financial Services·Credit Services
21.62%
of portfolio
Number of shares
210,000 sh
Holdings current value
$66.99M
Avg closing price
$231.55
+37.6%
Last action
Trimmed 40.8%
2025Q4
Current $318.55
3
M
MAMASTERCARD INCORPORATED
Financial Services·Credit Services
11.92%
of portfolio
Number of shares
65,750 sh
Holdings current value
$36.95M
Avg closing price
$441.16
+13.9%
Last action
Trimmed 28.1%
2025Q4
Current $502.38
4
B
BACBK OF AMERICA CORP
Financial Services·Banks - Diversified
11.73%
of portfolio
Number of shares
767,845 sh
Holdings current value
$36.33M
Avg closing price
$39.77
+31.9%
Last action
Exited
2025Q4
Current $52.47
5
N
N3167Y103FERRARI N V
8.06%
of portfolio
Number of shares
60,000 sh
Holdings current value
$24.97M
Avg closing price
$407.85
Last action
Trimmed 33.3%
2025Q4
Current —
6
M
MUMICRON TECHNOLOGY INC
Technology·Semiconductors
7.96%
of portfolio
Number of shares
200,000 sh
Holdings current value
$24.65M
Avg closing price
$131.53
+266.2%
Last action
Exited
2025Q4
Current $481.72
7
B
BRK.ABERKSHIRE HATHAWAY INC DEL
7.06%
of portfolio
Number of shares
30 sh
Holdings current value
$21.86M
Avg closing price
$612233
+15.3%
Last action
—
Current $706165
8
M
MCOMOODYS CORP
Financial Services·Financial Data & Stock Exchanges
4.37%
of portfolio
Number of shares
27,000 sh
Holdings current value
$13.54M
Avg closing price
$420.93
+7.5%
Last action
—
Current $452.35
9
B
BABAALIBABA GROUP HLDG LTDADR
Consumer Cyclical·Internet Retail
1.74%
of portfolio
Number of shares
47,500 sh
Holdings current value
$5.39M
Avg closing price
$72.00
+82.9%
Last action
Exited
2025Q4
Current $131.70
10
D
DJCODAILY JOURNAL CORP
Technology·Software - Application
1.57%
of portfolio
Number of shares
11,500 sh
Holdings current value
$4.86M
Avg closing price
$394.52
+34.2%
Last action
—
Current $529.50
11
G
GOOGLALPHABET INC
Communication Services·Internet Content & Information
0.91%
of portfolio
Number of shares
16,000 sh
Holdings current value
$2.82M
Avg closing price
$182.13
+86.1%
Last action
Exited
2025Q4
Current $338.89
12
S
SRGSERITAGE GROWTH PPTYS
0.50%
of portfolio
Number of shares
500,000 sh
Holdings current value
$1.54M
Avg closing price
$4.67
-44.8%
Last action
Exited
2025Q4
Current $2.58
13
A
AMRALPHA METALLURGICAL RESOUR I
Basic Materials·Coking Coal
0.29%
of portfolio
Number of shares
8,000 sh
Holdings current value
$900.0K
Avg closing price
$280.50
-29.1%
Last action
Exited
2025Q4
Current $198.91
14
C
CNRCORE NATURAL RESOURCES INC
Energy·Thermal Coal
0.24%
of portfolio
Number of shares
10,740 sh
Holdings current value
$749.0K
Avg closing price
$77.09
+13.3%
Last action
Exited
2025Q4
Current $87.38

Portfolio heatmap

Box size = % of portfolio · color = return since filing
BRK.B
22.04% · -3.1%
AXP
21.62% · -0.1%
MA
11.92% · -10.6%
BAC
11.73% · +10.9%
FERRARI N V
8.06%
MU
7.96% · +290.8%
BRK.A
7.06% · -3.1%
MCO
4.37% · -9.8%
BABA
1.74% · +16.1%
DJCO
1.57% · +25.4%
GOOGL
0.91% · +92.3%
SRG
0.50% · -16.2%
AMR
0.29% · +76.8%
CNR
0.24% · +25.3%

Sector exposure

Share of dollar value across the latest reported portfolio. Unclassified positions excluded.
  • Financial Services4 pos$153.8M79.6%
  • Technology2 pos$29.5M15.3%
  • Consumer Cyclical1 pos$5.4M2.8%
  • Communication Services1 pos$2.8M1.5%
  • Basic Materials1 pos$900K0.5%
  • Energy1 pos$749K0.4%
(37.7% unclassified, excluded from %)