Thompson Investment Management’s Iron Mountain IRM Stock Holding History

Thompson Investment Management’s Portfolio IRM Stock Details IRM Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q4	–	Sell	-264	Closed	-$26.9K	–	528
2025 Q3	$26.9K	Hold	264	–	–	﹤0.01%	346
2025 Q2	$27.1K	Hold	264	–	–	﹤0.01%	342
2025 Q1	$22.7K	Hold	264	–	–	﹤0.01%	342
2024 Q4	$27.7K	Sell	264 -800	-75%	-$94K	﹤0.01%	332
2024 Q3	$126K	Hold	1,064	–	–	0.02%	192
2024 Q2	$95.4K	Hold	1,064	–	–	0.01%	202
2024 Q1	$85.3K	Hold	1,064	–	–	0.01%	214
2023 Q4	$74.5K	Buy	1,064 +264	+33%	+$16.6K	0.01%	216
2023 Q3	$47.6K	Hold	800	–	–	0.01%	238
2023 Q2	$45.5K	Hold	800	–	–	0.01%	250
2023 Q1	$42.3K	Buy	+800	New	+$41.9K	0.01%	254
2022 Q1	–	Sell	-24,169	Closed	-$1.26M	–	196
2021 Q4	$1.26M	Sell	24,169 -1,970	-8%	-$93.1K	0.18%	107
2021 Q3	$1.14M	Sell	26,139 -340	-1%	-$15.3K	0.17%	105
2021 Q2	$1.12M	Sell	26,479 -135	-0.5%	-$5.66K	0.16%	107
2021 Q1	$985K	Buy	+26,614	New	+$890K	0.15%	109

Other funds holding IRM

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

Cohen & Steers New York $63.2B AUM 17.15% 1-Year Est. Return

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

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

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

Norges Bank Oslo, Norway $1T AUM

Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

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

Principal Financial Group Des Moines, Iowa $204B AUM 27.99% 1-Year Est. Return

Thompson Investment Management's IRM Position: Q4 2025 in Review

Thompson Investment Management sold out of Iron Mountain (IRM) in Q4 2025, closing a stake of 264 shares — an estimated $26.9K sold.

Thompson Investment Management first reported a position in IRM in Q1 2021 and held it in 15 quarters. The position peaked at $1.26M in Q4 2021. 1,011 funds tracked by Wall St. Rank hold IRM as of Q4 2025.

Thompson Investment Management reported no remaining Iron Mountain position as of Q4 2025 after selling out during the quarter.
Thompson Investment Management sold 264 Iron Mountain shares in Q4 2025, an estimated $26.9K.
Thompson Investment Management first reported a position in Iron Mountain in Q1 2021 and held it in 15 quarters.
Thompson Investment Management's Iron Mountain position peaked at $1.26M in Q4 2021.
1,011 funds tracked by Wall St. Rank held Iron Mountain as of Q4 2025.

Based on Thompson Investment Management's 13F filing for Q4 2025, filed 14 Jan 2026.