Guy Spier Aquamarine Zurich
Guy Spier is the founder of Aquamarine Capital and a well-known advocate of value investing in the Buffett-Munger tradition. He is the author of The Education of a Value Investor and is known for a patient, checklist-oriented process and limited portfolio turnover. Spier’s public holdings and writings attract individual investors who study behavioral discipline as much as stock picking.
Top Buys
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
American Express
AXP
|
+$51.9M |
| 2 |
Bank of America
BAC
|
+$39.6M |
| 3 |
Berkshire Hathaway Class B
BRK.B
|
+$21.4M |
| 4 |
Mastercard
MA
|
+$14.4M |
| 5 |
Micron Technology
MU
|
+$13.4M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Financials | 89.72% |
| 2 | Consumer Discretionary | 6.48% |
| 3 | Technology | 3.8% |
| 4 | Energy | 0% |
| 5 | Communication Services | 0% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
|
1
Berkshire Hathaway Class B
BRK.B
$1.06T
| $49.1M | 33.25% |
97,600
-43,000
| -31% | -$21.4M |
|
|
2
American Express
AXP
$227B
| $24M | 16.3% |
65,000
-145,000
| -69% | -$51.9M |
|
|
3
Mastercard
MA
$509B
| $22.8M | 15.48% |
40,000
-25,750
| -39% | -$14.4M |
|
|
4
Berkshire Hathaway Class A
BRK.A
$1.06T
| $22.6M | 15.35% |
30
| – | – |
|
5
Moody's
MCO
$87.2B
| $13.8M | 9.35% |
27,000
| – | – |
|
6
Ferrari
RACE
$76.7B
| $9.56M | 6.48% |
30,000
-30,000
| -50% | -$12M |
|
7
Daily Journal
DJCO
$827M
| $5.6M | 3.8% |
11,500
| – | – |
|
8
Alpha Metallurgical Resources
AMR
$2.66B
| – | – |
-8,000
| Closed | -$1.31M |
|
9
Alibaba
BABA
$286B
| – | – |
-47,500
| Closed | -$8.49M |
|
|
10
Bank of America
BAC
$431B
| – | – |
-767,845
| Closed | -$39.6M |
|
11
Alphabet (Google) Class A
GOOGL
$4.22T
| – | – |
-16,000
| Closed | -$3.89M |
|
|
12
Micron Technology
MU
$1.09T
| – | – |
-80,000
| Closed | -$13.4M |
|
|
SRG
13
Seritage Growth Properties
SRG
$120M
| – | – |
-500,000
| Closed | -$2.13M |
|
|
CNR
14
Core Natural Resources Inc
CNR
$4.72B
| – | – |
-10,740
| Closed | -$897K |
|
Similar funds
Guy Spier's Q4 2025 Portfolio in Review
As of Q4 2025, Guy Spier held 14 positions worth $148M, down 54% from $317M the previous quarter. Its ten largest holdings account for 100% of the portfolio.
Guy Spier withdrew a net $169M in Q4 2025, closing 7 positions and reducing 4 holdings. Its most notable exit was Bank of America, an estimated $39.6M position sold in full.
By sector, the portfolio is most concentrated in Financials at 90% of assets, up from 80% a quarter earlier, followed by Consumer Discretionary and Technology.
- Guy Spier's biggest Q4 2025 reduction was American Express, cutting an estimated $51.9M.
- Guy Spier fully exited Bank of America in Q4 2025, selling an estimated $39.6M.
- Guy Spier's ten largest holdings make up 100% of its $148M portfolio in Q4 2025.
- Guy Spier opened 0 new positions and closed 7 in Q4 2025.
- Guy Spier's portfolio value fell 54% quarter-over-quarter to $148M.
Based on Aquamarine Zurich's 13F filing for Q4 2025, filed 15 Jan 2026.