Iron Mountain Inc

IRM

Exchange: NYSE
Industry: Real Estate Investment Trusts
SEC CIK: 0001020569

SEC filings (opens in a new tab)

In the last 90 days, Iron Mountain Inc insiders filed 0 open-market purchases and 6 sales; 1,173 institutions reported holding it in 13F filings for Q2 2026, worth $32.4B in total; no superinvestor holds it.

13F holders, Q3 2026

Institutional positions in Iron Mountain Inc as of Sep 30, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Q3 2026 data is still coming in (13F filing deadline: Nov 16, 2026), so these numbers are incomplete.

Institutional holders: 3; +2 vs. Q2 2026
Shares held: 2.45K; +594 (+32.0%) vs. Q2 2026
Total value: $271.8K; +$37.4K (+16.0%) vs. Q2 2026
New holders: 2; 0 more added
Sold out: 0; 1 more reduced

1,172 institutions that held it in Q2 2026 haven't filed for Q3 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q2 2026: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting IRM on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holders

Value held

Institutions holding IRM and their total value by quarter
Quarter	Holders	Value
Q2 2026	1,173	$32.4B
Q1 2026	1,090	$25.9B
Q4 2025	1,011	$21.4B
Q3 2025	1,017	$25.5B
Q2 2025	1,045	$25.5B
Q1 2025	995	$21.1B
Q4 2024	1,067	$24.9B
Q3 2024	1,056	$28.8B
Q2 2024	967	$22.2B
Q1 2024	938	$19.0B
Q4 2023	891	$16.4B
Q3 2023	831	$13.7B
Q2 2023	817	$12.9B
Q1 2023	790	$12.0B
Q4 2022	782	$11.4B
Q3 2022	743	$10.0B
Q2 2022	767	$10.9B
Q1 2022	777	$12.4B
Q4 2021	754	$12.0B
Q3 2021	711	$9.94B
Q2 2021	687	$9.70B
Q1 2021	630	$8.44B

Institutions, Q3 2026

Shares, value and share of portfolio for each institution holding Iron Mountain Inc; share changes are against Q2 2026.

Institutions holding IRM in Q3 2026
Institution	Shares	Value	% of portfolio	Change in shares	Action
Border to Coast Pensions Partnership Ltd	–	–	–	–	Not filed
Victory Capital Management Inc	–	–	–	–	Not filed
Apollo Management Holdings, L.P.	–	–	–	–	Not filed
Aviva PLC	–	–	–	–	Not filed
Stifel Financial Corp	–	–	–	–	Not filed
State Board of Administration of Florida Retirement System	–	–	–	–	Not filed
Cetera Investment Advisers	–	–	–	–	Not filed
Federated Hermes, Inc.	–	–	–	–	Not filed
Americana Partners, LLC	–	–	–	–	Not filed
Summit Partners Public Asset Management, LLC	–	–	–	–	Not filed
Retirement Systems of Alabama	–	–	–	–	Not filed
Blair William & Co	–	–	–	–	Not filed
New York State Teachers Retirement System	–	–	–	–	Not filed
Korea Investment CORP	–	–	–	–	Not filed
CI Private Wealth, LLC	–	–	–	–	Not filed
Reaves W H & Co Inc	–	–	–	–	Not filed
Colony Group, LLC	–	–	–	–	Not filed
Captrust Financial Advisors	–	–	–	–	Not filed
Envestnet Asset Management Inc	–	–	–	–	Not filed
KLP Kapitalforvaltning AS	–	–	–	–	Not filed
Zurcher Kantonalbank (Zurich Cantonalbank)	–	–	–	–	Not filed
DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main	–	–	–	–	Not filed
GW&K Investment Management, LLC	–	–	–	–	Not filed
National Bank of Canada	–	–	–	–	Not filed
Handelsbanken Fonder AB	–	–	–	–	Not filed
New York State Common Retirement Fund	–	–	–	–	Not filed
Resona Asset Management Co.,Ltd.	–	–	–	–	Not filed
APG Asset Management N.V.	–	–	–	–	Not filed
State of Alaska, Department of Revenue	–	–	–	–	Not filed
Natixis Advisors, L.P.	–	–	–	–	Not filed
United Capital Financial Advisers, LLC	–	–	–	–	Not filed
Manufacturers Life Insurance Company, The	–	–	–	–	Not filed
Thrivent Financial for Lutherans	–	–	–	–	Not filed
Pacer Advisors, Inc.	–	–	–	–	Not filed
Ensign Peak Advisors, Inc	–	–	–	–	Not filed
Moran Wealth Management, LLC	–	–	–	–	Not filed
Tectonic Advisors LLC	–	–	–	–	Not filed
Danske Bank A/S	–	–	–	–	Not filed
State of Wisconsin Investment Board	–	–	–	–	Not filed
Commonwealth Equity Services, LLC	–	–	–	–	Not filed
Millennium Management LLC	–	–	–	–	Not filed
Vert Asset Management LLC	–	–	–	–	Not filed
Mariner, LLC	–	–	–	–	Not filed
Brookstone Capital Management	–	–	–	–	Not filed
BNP PARIBAS ASSET MANAGEMENT Holding S.A.	–	–	–	–	Not filed
FIL Ltd	–	–	–	–	Not filed
Public Employees Retirement Association of Colorado	–	–	–	–	Not filed
Chevy Chase Trust Holdings, Inc.	–	–	–	–	Not filed
Mitsubishi UFJ Trust & Banking Corp	–	–	–	–	Not filed
Franklin Resources Inc	–	–	–	–	Not filed
Royal London Asset Management Ltd	–	–	–	–	Not filed
Creative Planning	–	–	–	–	Not filed
Trust Co of Virginia	–	–	–	–	Not filed
Natixis	–	–	–	–	Not filed
Gillson Capital LP	–	–	–	–	Not filed
Sanctuary Advisors, LLC	–	–	–	–	Not filed
United Bank	–	–	–	–	Not filed
Toronto Dominion Bank	–	–	–	–	Not filed
Intech Investment Management LLC	–	–	–	–	Not filed
Tredje AP-fonden	–	–	–	–	Not filed
Sargent Investment Group, LLC	–	–	–	–	Not filed
Ar Asset Management Inc	–	–	–	–	Not filed
Mutual Advisors, LLC	–	–	–	–	Not filed
Treasurer of the State of North Carolina	–	–	–	–	Not filed
Boothbay Fund Management, LLC	–	–	–	–	Not filed
Point72 Asset Management, L.P.	–	–	–	–	Not filed
TCW Group Inc	–	–	–	–	Not filed
Eurizon Capital SGR S.p.A.	–	–	–	–	Not filed
Cambridge Investment Research Advisors, Inc.	–	–	–	–	Not filed
Storebrand Asset Management AS	–	–	–	–	Not filed
Omers Administration Corp	–	–	–	–	Not filed
IFM Investors Pty Ltd	–	–	–	–	Not filed
O'Neil Global Advisors, Inc.	–	–	–	–	Not filed
Sumitomo Mitsui DS Asset Management Company, Ltd	–	–	–	–	Not filed
First Trust Advisors LP	–	–	–	–	Not filed
Nippon Life Global Investors Americas, Inc.	–	–	–	–	Not filed
CIBC World Markets Inc.	–	–	–	–	Not filed
TD Asset Management Inc	–	–	–	–	Not filed
NEOS Investment Management LLC	–	–	–	–	Not filed
D. E. Shaw & Co., Inc.	–	–	–	–	Not filed
Panagora Asset Management Inc	–	–	–	–	Not filed
Mercer Global Advisors Inc	–	–	–	–	Not filed
HighTower Advisors, LLC	–	–	–	–	Not filed
Janney Montgomery Scott LLC	–	–	–	–	Not filed
Nykredit A/S	–	–	–	–	Not filed
Advisor Group Holdings, Inc.	–	–	–	–	Not filed
Adams Diversified Equity Fund, Inc.	–	–	–	–	Not filed
Kestra Advisory Services, LLC	–	–	–	–	Not filed
Uniplan Investment Counsel, Inc.	–	–	–	–	Not filed
Ieq Capital, LLC	–	–	–	–	Not filed
State of Tennessee, Treasury Department	–	–	–	–	Not filed
State of New Jersey Common Pension Fund D	–	–	–	–	Not filed
Cerity Partners LLC	–	–	–	–	Not filed
Lansforsakringar Fondforvaltning AB (publ)	–	–	–	–	Not filed
Schroder Investment Management Group	–	–	–	–	Not filed
KBC Group NV	–	–	–	–	Not filed
Nisa Investment Advisors, LLC	–	–	–	–	Not filed
Van Eck Associates Corp	–	–	–	–	Not filed
Nissay Asset Management Corp	–	–	–	–	Not filed
Arizona State Retirement System	–	–	–	–	Not filed