OpenStocks
Smart money
  • Super investors
  • Most popular stocks
  • Biggest buys
  • Biggest sells
  • New positions
  • Smart-money signals
Insiders
  • Insider trading
  • Browse insiders
  • Transactions feed
  • Insider trading RSS
Congress
  • Congress stock trades
  • All members of Congress
  • Trades by committee
  • Congress trades RSS
Markets
  • ETFs
  • Sectors
  • Industries
  • Stock screener
  • Daily market digest
  • Blog
Built from publicly disclosed institutional and insider activity. Informational purposes only - not investment advice.OpenStocks · v0.1
Logos by elbstream.com
  1. Home/
  2. Super Investors/
  3. Guy Spier (Aquamarine Zurich)
  • Overview
  • Portfolio7
  • Performance8Q
  • Options
  • Activity14
  • News

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 · 2026Q1
7 positions
1
B
BRK.BBERKSHIRE HATHAWAY INC DEL
34.57%
of portfolio
Number of shares
97,600 sh
Holdings current value
$46.8K
Avg closing price
$406.80
+15.7%
Last action
Trimmed 30.6%
2025Q4
Current $470.55
2
B
BRK.ABERKSHIRE HATHAWAY INC DEL
15.92%
of portfolio
Number of shares
30 sh
Holdings current value
$21.5K
Avg closing price
$612233
+15.3%
Last action
—
Current $706165
3
M
MAMASTERCARD INCORPORATED
Financial Services·Credit Services
14.77%
of portfolio
Number of shares
40,000 sh
Holdings current value
$20.0K
Avg closing price
$441.16
+13.9%
Last action
Trimmed 39.2%
2025Q4
Current $502.38
4
A
AXPAMERICAN EXPRESS CO
Financial Services·Credit Services
14.53%
of portfolio
Number of shares
65,000 sh
Holdings current value
$19.7K
Avg closing price
$231.55
+37.6%
Last action
Trimmed 69.0%
2025Q4
Current $318.55
5
M
MCOMOODYS CORP
Financial Services·Financial Data & Stock Exchanges
8.71%
of portfolio
Number of shares
27,000 sh
Holdings current value
$11.8K
Avg closing price
$420.93
+7.5%
Last action
—
Current $452.35
6
N
N3167Y103FERRARI N V
7.40%
of portfolio
Number of shares
30,000 sh
Holdings current value
$10.0K
Avg closing price
$407.85
Last action
Trimmed 50.0%
2025Q4
Current —
7
D
DJCODAILY JOURNAL CORP
Technology·Software - Application
4.10%
of portfolio
Number of shares
11,500 sh
Holdings current value
$5.5K
Avg closing price
$394.52
+34.2%
Last action
—
Current $529.50

Portfolio heatmap

Box size = % of portfolio · color = return since filing
BRK.B
34.57% · +98094.7%
BRK.A
15.92% · +98233.4%
MA
14.77% · +100446.4%
AXP
14.53% · +105213.8%
MCO
8.71% · +103588.3%
FERRARI N V
7.40%
DJCO
4.10% · +109675.6%

Sector exposure

Share of dollar value across the latest reported portfolio. Unclassified positions excluded.
  • Financial Services3 pos$51K90.3%
  • Technology1 pos$6K9.7%
(57.9% unclassified, excluded from %)