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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 8 sales; 1,173 institutions reported holding it in 13F filings for Q2 2026, worth $32.4B in total; no superinvestor holds it.

13F holders, Q4 2025

Institutional positions in Iron Mountain Inc as of Dec 31, 2025. 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

Institutional holders
1,011
+16 vs. Q3 2025
Shares held
257.3M
+7.46M (+3.0%) vs. Q3 2025
Total value
$21.4B
−$4.12B (−16.2%) vs. Q3 2025
New holders
123
326 more added
Sold out
107
407 more reduced

22 institutions that held it in Q3 2025 haven't filed for Q4 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q3 2025: 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 holdersQ4 2025: 1,011 institutions
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 heldQ4 2025: $21.4B
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, Q4 2025

Shares, value and share of portfolio for each institution holding Iron Mountain Inc; share changes are against Q3 2025.

Institutions holding IRM in Q4 2025
InstitutionSharesValue% of portfolioChange in sharesAction
Vanguard Group Inc46,627,483$3.87B0.06%−625,617−1.3%Reduced
BlackRock, Inc.32,919,658$2.73B0.05%+1,210,594+3.8%Added
Cohen & Steers, Inc.18,903,716$1.57B2.83%+3,155,034+20.0%Added
State Street Corp16,888,798$1.42B0.05%−242,989−1.4%Reduced
Geode Capital Management, LLC8,292,653$685.4M0.04%+102,073+1.2%Added
FMR LLC7,984,304$662.3M0.03%+126,212+1.6%Added
Norges Bank4,447,133$368.9M0.04%+4,447,133New
Dimensional Fund Advisors LP4,429,359$367.4M0.08%+81,320+1.9%Added
Invesco Ltd.4,417,367$366.4M0.03%−649,149−12.8%Reduced
Principal Financial Group Inc4,207,596$349.0M0.18%+1,680,438+66.5%Added
Northern Trust Corp4,152,569$344.5M0.04%+121,003+3.0%Added
Charles Schwab Investment Management Inc3,880,275$321.9M0.05%+206,030+5.6%Added
Daiwa Securities Group Inc.3,654,086$303.1M0.98%+502,998+16.0%Added
Morgan Stanley3,598,973$298.5M0.02%−12,426−0.3%Reduced
Legal & General Group Plc3,356,420$278.4M0.06%+140,965+4.4%Added
Contour Asset Management LLC2,832,182$234.9M5.48%−333,648−10.5%Reduced
Centersquare Investment Management LLC2,631,453$218.3M2.15%+116,989+4.7%Added
Deutsche Bank AG2,541,992$210.9M0.07%−348,459−12.1%Reduced
Prudential Financial Inc2,310,481$191.7M0.23%+196,864+9.3%Added
Pictet Asset Management Holding SA2,295,965$190.4M0.18%−168,203−6.8%Reduced
Nuveen, LLC2,127,931$176.5M0.05%−14,574−0.7%Reduced
Capital World Investors2,117,169$175.6M0.02%00.0%Unchanged
JPMorgan Chase & Co1,927,935$159.9M0.01%−128,513−6.2%Reduced
Ameriprise Financial Inc1,744,405$142.5M0.03%+38,373+2.2%Added
Vontobel Holding Ltd.1,689,246$140.1M0.46%+610,759+56.6%Added
Bank of New York Mellon Corp1,685,978$139.9M0.02%+19,418+1.2%Added
PGGM Investments1,657,159$137.5M2.18%−27,622−1.6%Reduced
Duff & Phelps Investment Management Co1,580,452$131.1M1.49%−61,622−3.8%Reduced
Goldman Sachs Group Inc1,525,240$126.5M0.02%+171,143+12.6%Added
Bank of America Corp1,510,345$125.3M0.01%+282,395+23.0%Added
Cbre Clarion Securities LLC1,446,597$120.0M1.76%+177,130+14.0%Added
Russell Investments Group, Ltd.1,405,760$116.6M0.13%−300,675−17.6%Reduced
Amundi1,333,693$110.6M0.03%+248,386+22.9%Added
Royal Bank of Canada1,285,871$106.7M0.02%−1,013,112−44.1%Reduced
DekaBank Deutsche Girozentrale1,122,500$95.8M0.18%00.0%Unchanged
Citadel Advisors LLC1,119,371$92.9M0.06%+1,058,080+1,726.3%Added
HSBC Holdings PLC1,055,775$87.6M0.05%+104,199+11.0%Added
SEI Investments Co1,024,664$85.0M0.08%+151,794+17.4%Added
AQR Capital Management LLC923,196$76.6M0.04%+465,724+101.8%Added
Sumitomo Mitsui Trust Holdings, Inc.906,888$75.2M0.04%−27,864−3.0%Reduced
Mitsubishi UFJ Kokusai Asset Management Co., Ltd.839,566$69.9M0.05%+37,254+4.6%Added
Swiss National Bank809,261$67.1M0.04%−41,300−4.9%Reduced
UBS Group AG795,908$66.0M0.01%−640,393−44.6%Reduced
Point72 Asset Management, L.P.790,504$65.6M0.10%−506,027−39.0%Reduced
Barclays PLC728,857$60.5M0.02%−11,033−1.5%Reduced
CIBC Private Wealth Group, LLC677,651$56.2M0.10%−43,436−6.0%Reduced
Adage Capital Partners GP, L.L.C.656,852$54.5M0.08%+103,432+18.7%Added
Welch & Forbes LLC656,364$54.4M0.66%−2,628−0.4%Reduced
Wells Fargo & Company637,272$52.9M0.01%−568−0.1%Reduced
LPL Financial LLC634,799$52.7M0.01%−74,601−10.5%Reduced
Epoch Investment Partners, Inc.629,854$52.2M0.30%−20,903−3.2%Reduced
Universal- Beteiligungs- und Servicegesellschaft mbH625,444$52.0M0.08%+127,724+25.7%Added
Price T Rowe Associates Inc606,859$50.3M0.01%+11,264+1.9%Added
Rhumbline Advisers590,540$49.0M0.04%−6,097−1.0%Reduced
APG Asset Management US Inc.582,174$48.3M0.38%00.0%Unchanged
BNP Paribas Arbitrage, SA562,253$46.6M0.03%+35,983+6.8%Added
Asset Management One Co.,Ltd.555,974$45.9M0.13%+4,260+0.8%Added
Alliancebernstein L.P.544,810$45.2M0.01%−11,184−2.0%Reduced
Nomura Asset Management Co Ltd544,483$45.2M0.11%+15,435+2.9%Added
California Public Employees Retirement System513,555$42.6M0.02%+1400.0%Added
National Pension Service509,020$42.2M0.03%+13,540+2.7%Added
Border to Coast Pensions Partnership Ltd500,000$41.6M0.72%+20,000+4.2%Added
DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main495,760$41.1M0.04%−19,246−3.7%Reduced
Heitman Real Estate Securities LLC490,548$40.7M2.86%+16,180+3.4%Added
Millennium Management LLC489,014$40.6M0.03%+3,597+0.7%Added
Bank of Montreal436,345$36.2M0.01%+38,165+9.6%Added
California State Teachers Retirement System434,105$36.0M0.04%−6,452−1.5%Reduced
Neuberger Berman Group LLC431,386$35.8M0.03%+15,138+3.6%Added
STRS Ohio414,128$34.4M0.13%+156,613+60.8%Added
Rockefeller Capital Management L.P.403,992$33.6M0.06%−3,463−0.8%Reduced
American Century Companies Inc395,893$32.8M0.02%−156,156−28.3%Reduced
Raymond James Financial Inc366,309$30.4M0.01%−14,039−3.7%Reduced
Standard Life Aberdeen plc364,889$30.3M0.05%−17,745−4.6%Reduced
Adelante Capital Management LLC339,227$28.1M1.96%−47,058−12.2%Reduced
Great West Life Assurance Co336,935$27.9M0.05%−108,129−24.3%Reduced
Teacher Retirement System of Texas333,971$27.7M0.10%+295,333+764.4%Added
Citigroup Inc318,601$26.4M0.02%−101,122−24.1%Reduced
Adell Harriman & Carpenter Inc314,617$26.1M1.56%−11,698−3.6%Reduced
Marble Harbor Investment Counsel, LLC314,020$26.0M2.78%−11,240−3.5%Reduced
Macquarie Group Ltd292,992$24.3M0.11%+6,408+2.2%Added
Two Sigma Investments, LP290,160$24.1M0.04%+290,160New
Swedbank AB284,858$23.6M0.02%00.0%Unchanged
Apollo Management Holdings, L.P.265,539$22.0M0.22%+265,539New
State Board of Administration of Florida Retirement System262,515$21.8M0.04%−8,242−3.0%Reduced
Aviva PLC256,125$21.2M0.04%+13,676+5.6%Added
Captrust Financial Advisors255,142$21.2M0.04%−513,124−66.8%Reduced
Cetera Investment Advisers248,597$20.6M0.02%−5,755−2.3%Reduced
Americana Partners, LLC241,349$20.0M0.55%+241,349New
Blair William & Co238,285$19.8M0.05%−80,125−25.2%Reduced
Brookstone Capital Management235,933$19.6M0.22%+28,490+13.7%Added
Retirement Systems of Alabama228,071$18.9M0.06%−2,868−1.2%Reduced
New York State Teachers Retirement System227,876$18.9M0.04%+60.0%Added
Stifel Financial Corp227,234$18.8M0.02%+9,097+4.2%Added
Pacer Advisors, Inc.223,367$18.5M0.05%−7,868−3.4%Reduced
Colony Group, LLC217,915$18.3M0.02%+88,319+68.1%Added
Regions Financial Corp214,642$17.8M0.11%−37,139−14.8%Reduced
CI Private Wealth, LLC211,327$17.5M0.02%+8,803+4.3%Added
Schonfeld Strategic Advisors LLC209,300$17.4M0.09%+111,071+113.1%Added
Verition Fund Management LLC208,951$17.3M0.09%+181,051+648.9%Added
CIBC World Markets Inc.208,036$17.3M0.03%+35,586+20.6%Added