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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 · 2024Q4
14 positions
1
B
BRK.BBERKSHIRE HATHAWAY INC DEL
22.16%
of portfolio
Number of shares
140,600 sh
Holdings current value
$63.73M
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
21.67%
of portfolio
Number of shares
210,000 sh
Holdings current value
$62.33M
Avg closing price
$231.55
+37.6%
Last action
Trimmed 40.8%
2025Q4
Current $318.55
3
M
MAMASTERCARD INCORPORATED
Financial Services·Credit Services
12.04%
of portfolio
Number of shares
65,750 sh
Holdings current value
$34.62M
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
$33.75M
Avg closing price
$39.77
+31.9%
Last action
Exited
2025Q4
Current $52.47
5
N
N3167Y103FERRARI N V
8.60%
of portfolio
Number of shares
60,000 sh
Holdings current value
$24.74M
Avg closing price
$407.85
Last action
Trimmed 33.3%
2025Q4
Current —
6
B
BRK.ABERKSHIRE HATHAWAY INC DEL
7.10%
of portfolio
Number of shares
30 sh
Holdings current value
$20.43M
Avg closing price
$612233
+15.3%
Last action
—
Current $706165
7
M
MUMICRON TECHNOLOGY INC
Technology·Semiconductors
5.85%
of portfolio
Number of shares
200,000 sh
Holdings current value
$16.83M
Avg closing price
$131.53
+266.2%
Last action
Exited
2025Q4
Current $481.72
8
M
MCOMOODYS CORP
Financial Services·Financial Data & Stock Exchanges
4.44%
of portfolio
Number of shares
27,000 sh
Holdings current value
$12.78M
Avg closing price
$420.93
+7.5%
Last action
—
Current $452.35
9
D
DJCODAILY JOURNAL CORP
Technology·Software - Application
2.27%
of portfolio
Number of shares
11,500 sh
Holdings current value
$6.53M
Avg closing price
$394.52
+34.2%
Last action
—
Current $529.50
10
B
BABAALIBABA GROUP HLDG LTDADR
Consumer Cyclical·Internet Retail
1.40%
of portfolio
Number of shares
47,500 sh
Holdings current value
$4.03M
Avg closing price
$72.00
+82.9%
Last action
Exited
2025Q4
Current $131.70
11
G
GOOGLALPHABET INC
Communication Services·Internet Content & Information
1.05%
of portfolio
Number of shares
16,000 sh
Holdings current value
$3.03M
Avg closing price
$182.13
+86.1%
Last action
Exited
2025Q4
Current $338.89
12
S
SRGSERITAGE GROWTH PPTYS
0.72%
of portfolio
Number of shares
500,000 sh
Holdings current value
$2.06M
Avg closing price
$4.67
-44.8%
Last action
Exited
2025Q4
Current $2.58
13
A
AMRALPHA METALLURGICAL RESOUR I
Basic Materials·Coking Coal
0.56%
of portfolio
Number of shares
8,000 sh
Holdings current value
$1.60M
Avg closing price
$280.50
-29.1%
Last action
Exited
2025Q4
Current $198.91
14
A
ARCH1USDARCH RESOURCES INC
0.40%
of portfolio
Number of shares
8,100 sh
Holdings current value
$1.14M
Avg closing price
$152.22
Last action
Exited
2025Q1
Current —

Portfolio heatmap

Box size = % of portfolio · color = return since filing
BRK.B
22.16% · +3.8%
AXP
21.67% · +7.3%
MA
12.04% · -4.6%
BAC
11.73% · +19.4%
FERRARI N V
8.60%
BRK.A
7.10% · +3.7%
MU
5.85% · +472.4%
MCO
4.44% · -4.4%
DJCO
2.27% · -6.8%
BABA
1.40% · +55.3%
GOOGL
1.05% · +79.0%
SRG
0.72% · -37.4%
AMR
0.56% · -0.6%
ARCH1USD
0.40%

Sector exposure

Share of dollar value across the latest reported portfolio. Unclassified positions excluded.
  • Financial Services4 pos$143.5M81.8%
  • Technology2 pos$23.4M13.3%
  • Consumer Cyclical1 pos$4.0M2.3%
  • Communication Services1 pos$3.0M1.7%
  • Basic Materials1 pos$1.6M0.9%
(39.0% unclassified, excluded from %)