Guy Spier’s Micron Technology MU Stock Holding History

Guy Spier’s Portfolio MU Stock Details MU Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q4	–	Sell	-80,000	Closed	-$13.4M	–	12
2025 Q3	$13.4M	Sell	80,000 -120,000	-60%	-$15.4M	4.22%	7
2025 Q2	$24.6M	Hold	200,000	–	–	7.96%	6
2025 Q1	$17.4M	Hold	200,000	–	–	5.92%	7
2024 Q4	$16.8M	Hold	200,000	–	–	5.85%	7
2024 Q3	$20.7M	Hold	200,000	–	–	7.26%	6
2024 Q2	$26.3M	Hold	200,000	–	–	10.02%	5
2024 Q1	$23.6M	Hold	200,000	–	–	9%	6
2023 Q4	$17.1M	Hold	200,000	–	–	7.46%	6
2023 Q3	$13.6M	Hold	200,000	–	–	6.71%	7
2023 Q2	$12.6M	Hold	200,000	–	–	6.02%	7
2023 Q1	$12.1M	Hold	200,000	–	–	6.24%	7
2022 Q4	$10M	Hold	200,000	–	–	5.38%	7
2022 Q3	$10M	Buy	+200,000	New	+$11.6M	6.1%	7

Other funds holding MU

Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return

Norges Bank Oslo, Norway $1T AUM

Capital International Investors Los Angeles, California $484B AUM 34.9% 1-Year Est. Return

Guy Spier's MU Position: Q4 2025 in Review

Guy Spier sold out of Micron Technology (MU) in Q4 2025, closing a stake of 80,000 shares — an estimated $13.4M sold.

Guy Spier first reported a position in MU in Q3 2022 and held it in 13 quarters. The position peaked at $26.3M in Q2 2024. 2,689 funds tracked by Wall St. Rank hold MU as of Q4 2025.

Guy Spier reported no remaining Micron Technology position as of Q4 2025 after selling out during the quarter.
Guy Spier sold 80,000 Micron Technology shares in Q4 2025, an estimated $13.4M.
Guy Spier first reported a position in Micron Technology in Q3 2022 and held it in 13 quarters.
Guy Spier's Micron Technology position peaked at $26.3M in Q2 2024.
2,689 funds tracked by Wall St. Rank held Micron Technology as of Q4 2025.

Based on Aquamarine Zurich's 13F filing for Q4 2025, filed 15 Jan 2026.