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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/
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  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

Not enough filing history to compute mark-to-market returns for Guy Spier.

We need at least one year of portfolio coverage with priceable positions.

Performance overview

We mark Guy Spier (Aquamarine Zurich)'s disclosed portfolio to current market prices and compare its growth against the S&P 500 (SPY). Guy’s portfolio is 53.6% since 2024Q2.

Portfolio growth vs SPY
Rebased to 100 at 2024Q2 · through 2026Q1
Guy Spier
-63.2%
SPY
+22.0%
Alpha
-85.2pp
2857871161452024Q22025Q12026Q1
Portfolio line is the GIPS-compliant time-weighted return chain-linked across the manager's quarterly 13F filings — unaffected by capital flows. Quarters with insufficient held-through coverage are skipped, which can briefly flatten the line.
Capital flow per quarter
BuysSellsNet
+$70M+$35M$0-$35M-$70M'24Q3'24Q4'25Q1'25Q2'25Q3'25Q4'26Q1
Latest · 2026Q1
$0
Lifetime buys
$828K
Lifetime sells
$91M
Portfolio over time
AUMPositions
$0$105M$209M$317M147'24Q2'25Q1'26Q1
QoQ AUM
-8.3%
8Q lifetime AUM
-99.9%
QoQ positions
+0
8Q lifetime positions
-7
Position concentration
7 positions
Top 1
35%
of book
  • Top 135%$47KBRK.B
  • Top 2-554%$73KBRK.A, MA, AXP
  • Top 6-1012%$16KFERRARI N V, DJCO
  • Top 11-200%$0—
  • Rest0%$0—