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Micron Technology Inc

MU

Micron Technology Inc

Micron Technology Inc historical holders

total: 21

Aquamarine Capital Micron Technology Inc transactions over time

Total transactions:
4
New positions:
1
Sold out:
1
Added:
1
Reduced:
1
Held since:
2019 Q3
Held for:
25 quarters
Latest activity:
2025 Q4
Guy Spier has been an institutional investor in Micron Technology Inc (MU) since 2019 Q3. According to 2026 Q2 report, Guy Spier doesn't hold any shares. The fund/company first acquired MU in 2019 Q3, initially purchasing 120,000 shares. Since the initial investment, Aquamarine Capital has made 3 more transactions in this position.

When did Guy Spier exit their MU position?

Guy Spier no longer holds Micron Technology Inc (MU). They sold off their entire position in 2025 Q4, closing out an investment that began in 2019 Q3.

When did Guy Spier first invest in MU?

Guy Spier first invested in Micron Technology Inc (MU) in 2019 Q3 at the reported quarter-end price of $42.85 per share, acquiring 120,000 shares in their initial purchase.

What is Guy Spier's average cost basis for MU?

Based on historical transaction data, Guy Spier's estimated cost basis for Micron Technology Inc (MU) is approximately $55.78 per share. This represents their average reported price* across all buy transactions.

Estimated cost basis*

Weighted AVG buy price:
$55.78
Weighted AVG sell price:
$167.32

MU transactions history by Aquamarine Capital

4 results
Period % of
portfolio
Shares
held after*
Reported
price*
Value* % (shares)
of activity
% change
to portfolio
2025 Q4
0.00%
0
$167.32
-100% (-80,000)
-4.22%
2025 Q3
4.22%
80,000
$167.32
$13,386,000
-60.00% (-120,000)
-6.48%
2020 Q4
8.77%
$75.18
+66.67% (+80,000)
2019 Q3
2.60%
$42.85
new
* Shares, change to shares, sold shares, shares held after: split-adjusted.
* Reported price: this doesn't represent the actual buy or sell price. It is the split-adjusted price of the security as of the last day of the reported period.
If the security is completely sold out, we show the reported split-adjusted price prior to the actual period.
* Estimated cost basis: based on "Reported price*" (not earlier than 2013 Q2). Calculation starts from the latest "new buy" activity to the latest "close out" activity (if any).
* Value or Price: If the security is completely sold out, we show the reported value (or price) prior to the actual period.
* New buy or own: this means there is no earlier reporting (for us or in general). So we can't know if the actual purchase of the security happened at the reported period or earlier.