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Iron Mountain Inc

IRM
Exchange
NYSE
Industry
Real Estate Investment Trusts
SEC CIK
0001020569

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
Q1 2021: 630 institutionsQ2 2021: 687 institutionsQ3 2021: 711 institutionsQ4 2021: 754 institutionsQ1 2022: 777 institutionsQ2 2022: 767 institutionsQ3 2022: 743 institutionsQ4 2022: 782 institutionsQ1 2023: 790 institutionsQ2 2023: 817 institutionsQ3 2023: 831 institutionsQ4 2023: 891 institutionsQ1 2024: 938 institutionsQ2 2024: 967 institutionsQ3 2024: 1,056 institutionsQ4 2024: 1,067 institutionsQ1 2025: 995 institutionsQ2 2025: 1,045 institutionsQ3 2025: 1,017 institutionsQ4 2025: 1,011 institutionsQ1 2026: 1,090 institutionsQ2 2026: 1,173 institutions
Value held
Q1 2021: $8.44BQ2 2021: $9.70BQ3 2021: $9.94BQ4 2021: $12.0BQ1 2022: $12.4BQ2 2022: $10.9BQ3 2022: $10.0BQ4 2022: $11.4BQ1 2023: $12.0BQ2 2023: $12.9BQ3 2023: $13.7BQ4 2023: $16.4BQ1 2024: $19.0BQ2 2024: $22.2BQ3 2024: $28.8BQ4 2024: $24.9BQ1 2025: $21.1BQ2 2025: $25.5BQ3 2025: $25.5BQ4 2025: $21.4BQ1 2026: $25.9BQ2 2026: $32.4B
Institutions holding IRM and their total value by quarter
QuarterHoldersValue
Q2 20261,173$32.4B
Q1 20261,090$25.9B
Q4 20251,011$21.4B
Q3 20251,017$25.5B
Q2 20251,045$25.5B
Q1 2025995$21.1B
Q4 20241,067$24.9B
Q3 20241,056$28.8B
Q2 2024967$22.2B
Q1 2024938$19.0B
Q4 2023891$16.4B
Q3 2023831$13.7B
Q2 2023817$12.9B
Q1 2023790$12.0B
Q4 2022782$11.4B
Q3 2022743$10.0B
Q2 2022767$10.9B
Q1 2022777$12.4B
Q4 2021754$12.0B
Q3 2021711$9.94B
Q2 2021687$9.70B
Q1 2021630$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
InstitutionSharesValue% of portfolioChange in sharesAction
Coastline Trust Co1,640$182.0K0.02%−216−11.6%Reduced
Sarver Vrooman Wealth Advisors610$67.7K0.04%+610New
Hickory Point Bank & Trust200$22.2K0.01%+200New
BlackRock, Inc.––––Not filed
Vanguard Portfolio Management LLC––––Not filed
Vanguard Capital Management LLC––––Not filed
State Street Corp––––Not filed
Cohen & Steers, Inc.––––Not filed
Geode Capital Management, LLC––––Not filed
FMR LLC––––Not filed
Dimensional Fund Advisors LP––––Not filed
Morgan Stanley––––Not filed
Principal Financial Group Inc––––Not filed
Charles Schwab Investment Management Inc––––Not filed
Northern Trust Corp––––Not filed
Norges Bank––––Not filed
Invesco Ltd.––––Not filed
Legal & General Group Plc––––Not filed
UBS Asset Management Americas Inc––––Not filed
Deutsche Bank AG––––Not filed
Goldman Sachs Group Inc––––Not filed
Centersquare Investment Management LLC––––Not filed
JPMorgan Chase & Co––––Not filed
Nuveen, LLC––––Not filed
AQR Capital Management LLC––––Not filed
Prudential Financial Inc––––Not filed
Vontobel Holding Ltd.––––Not filed
Daiwa Securities Group Inc.––––Not filed
Ameriprise Financial Inc––––Not filed
Vanguard Fiduciary Trust Co––––Not filed
Royal Bank of Canada––––Not filed
Bank of New York Mellon Corp––––Not filed
Duff & Phelps Investment Management Co––––Not filed
Russell Investments Group, Ltd.––––Not filed
HSBC Holdings PLC––––Not filed
Contour Asset Management LLC––––Not filed
Capital World Investors––––Not filed
Amundi––––Not filed
American Century Companies Inc––––Not filed
Bank of America Corp––––Not filed
Cbre Clarion Securities LLC––––Not filed
Mitsubishi UFJ Kokusai Asset Management Co., Ltd.––––Not filed
UBS Group AG––––Not filed
DekaBank Deutsche Girozentrale––––Not filed
Sumitomo Mitsui Trust Holdings, Inc.––––Not filed
Swiss National Bank––––Not filed
Pictet Asset Management Holding SA––––Not filed
CIBC Bancorp USA Inc.––––Not filed
Barclays PLC––––Not filed
SEI Investments Co––––Not filed
Standard Life Aberdeen plc––––Not filed
APG Asset Management US Inc.––––Not filed
PGGM Investments––––Not filed
Wells Fargo & Company––––Not filed
BNP Paribas Arbitrage, SA––––Not filed
Vanguard Global Advisers, LLC––––Not filed
LPL Financial LLC––––Not filed
Welch & Forbes LLC––––Not filed
Price T Rowe Associates Inc––––Not filed
Universal- Beteiligungs- und Servicegesellschaft mbH––––Not filed
Quantinno Capital Management LP––––Not filed
Nomura Asset Management Co Ltd––––Not filed
Rhumbline Advisers––––Not filed
Vanguard Asset Management, Ltd––––Not filed
Raymond James Financial Inc––––Not filed
Asset Management One Co.,Ltd.––––Not filed
California Public Employees Retirement System––––Not filed
Nomura Asset Management International Inc.––––Not filed
Worldquant Millennium Advisors LLC––––Not filed
Adage Capital Partners GP, L.L.C.––––Not filed
Wellington Management Group LLP––––Not filed
Clark Capital Management Group, Inc.––––Not filed
Colony Capital, Inc.––––Not filed
Alliancebernstein L.P.––––Not filed
National Pension Service––––Not filed
Bank of Montreal––––Not filed
Healthcare of Ontario Pension Plan Trust Fund––––Not filed
Virginia Retirement Systems Et Al––––Not filed
California State Teachers Retirement System––––Not filed
Public Employees Retirement System of Ohio––––Not filed
Citigroup Inc––––Not filed
Voloridge Investment Management, LLC––––Not filed
Jane Street Group, LLC––––Not filed
Rockefeller Capital Management L.P.––––Not filed
Heitman Real Estate Securities LLC––––Not filed
Great West Life Assurance Co––––Not filed
Vanguard Investments Australia, Ltd.––––Not filed
Citadel Advisors LLC––––Not filed
Adelante Capital Management LLC––––Not filed
Adell Harriman & Carpenter Inc––––Not filed
Bamco Inc––––Not filed
Robeco Institutional Asset Management B.V.––––Not filed
Teacher Retirement System of Texas––––Not filed
Marble Harbor Investment Counsel, LLC––––Not filed
Acadian Asset Management LLC––––Not filed
Neuberger Berman Group LLC––––Not filed
Swedbank AB––––Not filed
Commonwealth of Pennsylvania Public School Empls Retrmt Sys––––Not filed
SG Americas Securities, LLC––––Not filed
Macquarie Group Ltd––––Not filed