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, Q1 2026
Institutional positions in Iron Mountain Inc as of Mar 31, 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
- Institutional holders
- 1,090
- +87 vs. Q4 2025
- Shares held
- 253.3M
- +47.9M (+23.4%) vs. Q4 2025
- Total value
- $25.9B
- +$8.81B (+51.7%) vs. Q4 2025
- New holders
- 179
- 401 more added
- Sold out
- 92
- 348 more reduced
8 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q4 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.
| 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, Q1 2026
Shares, value and share of portfolio for each institution holding Iron Mountain Inc; share changes are against Q4 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Ensign Peak Advisors, Inc | 297,330 | $30.4M | 0.06% | +222,713+298.5% | Added |
| Marble Harbor Investment Counsel, LLC | 300,474 | $30.7M | 3.33% | −13,546−4.3% | Reduced |
| Citigroup Inc | 315,634 | $32.2M | 0.02% | −2,967−0.9% | Reduced |
| Adell Harriman & Carpenter Inc | 315,817 | $32.3M | 1.97% | +1,200+0.4% | Added |
| Quantinno Capital Management LP | 322,017 | $32.9M | 0.05% | +154,910+92.7% | Added |
| Great West Life Assurance Co | 335,860 | $34.4M | 0.06% | −1,075−0.3% | Reduced |
| Vanguard Investments Australia, Ltd. | 343,334 | $35.1M | 0.10% | +343,334 | New |
| Wellington Management Group LLP | 347,915 | $35.5M | 0.01% | +243,788+234.1% | Added |
| Adelante Capital Management LLC | 356,934 | $36.5M | 2.58% | +17,707+5.2% | Added |
| Neuberger Berman Group LLC | 360,751 | $36.8M | 0.03% | −70,635−16.4% | Reduced |
| Standard Life Aberdeen plc | 371,208 | $37.9M | 0.06% | +6,319+1.7% | Added |
| Millennium Management LLC | 374,463 | $38.2M | 0.03% | −114,551−23.4% | Reduced |
| Citadel Advisors LLC | 374,954 | $38.3M | 0.03% | −744,417−66.5% | Reduced |
| Point72 Asset Management, L.P. | 377,618 | $38.6M | 0.07% | −412,886−52.2% | Reduced |
| Rockefeller Capital Management L.P. | 389,140 | $39.7M | 0.07% | −14,852−3.7% | Reduced |
| Teacher Retirement System of Texas | 394,701 | $40.3M | 0.17% | +60,730+18.2% | Added |
| Bank of Montreal | 406,013 | $41.5M | 0.02% | −30,332−7.0% | Reduced |
| California State Teachers Retirement System | 422,871 | $43.2M | 0.05% | −11,234−2.6% | Reduced |
| Public Employees Retirement System of Ohio | 423,714 | $43.3M | 0.14% | +232,207+121.3% | Added |
| National Pension Service | 429,392 | $43.9M | 0.03% | −79,628−15.6% | Reduced |
| Virginia Retirement Systems Et Al | 440,108 | $45.0M | 0.33% | +315,308+252.7% | Added |
| Alliancebernstein L.P. | 565,255 | $46.9M | 0.02% | +20,445+3.8% | Added |
| Clark Capital Management Group, Inc. | 468,365 | $47.8M | 0.30% | +468,365 | New |
| Border to Coast Pensions Partnership Ltd | 470,000 | $48.2M | 0.81% | −30,000−6.0% | Reduced |
| California Public Employees Retirement System | 502,460 | $51.3M | 0.03% | −11,095−2.2% | Reduced |
| Colony Capital, Inc. | 504,021 | $51.5M | 3.27% | +504,021 | New |
| Vanguard Asset Management, Ltd | 504,995 | $51.6M | 0.04% | +504,995 | New |
| BNP Paribas Arbitrage, SA | 508,511 | $51.9M | 0.03% | −53,742−9.6% | Reduced |
| Bamco Inc | 525,270 | $53.7M | 0.16% | +525,270 | New |
| Asset Management One Co.,Ltd. | 547,474 | $55.9M | 0.16% | −8,500−1.5% | Reduced |
| Worldquant Millennium Advisors LLC | 548,049 | $56.0M | 0.22% | +392,013+251.2% | Added |
| Nomura Asset Management Co Ltd | 563,343 | $57.5M | 0.15% | +18,860+3.5% | Added |
| Rhumbline Advisers | 578,543 | $59.1M | 0.05% | −11,997−2.0% | Reduced |
| Nomura Asset Management International Inc. | 586,881 | $59.9M | 0.10% | +502,658+596.8% | Added |
| Adage Capital Partners GP, L.L.C. | 590,052 | $60.3M | 0.09% | −66,800−10.2% | Reduced |
| Universal- Beteiligungs- und Servicegesellschaft mbH | 590,504 | $60.3M | 0.10% | −34,940−5.6% | Reduced |
| Price T Rowe Associates Inc | 601,581 | $61.4M | 0.01% | −5,278−0.9% | Reduced |
| Epoch Investment Partners, Inc. | 616,513 | $63.0M | 0.38% | −13,341−2.1% | Reduced |
| LPL Financial LLC | 621,238 | $63.5M | 0.02% | −13,561−2.1% | Reduced |
| Vanguard Global Advisers, LLC | 647,775 | $66.2M | 0.04% | +647,775 | New |
| Welch & Forbes LLC | 652,068 | $66.6M | 0.86% | −4,296−0.7% | Reduced |
| Wells Fargo & Company | 658,454 | $67.3M | 0.01% | +21,182+3.3% | Added |
| Barclays PLC | 673,771 | $68.8M | 0.02% | −55,086−7.6% | Reduced |
| APG Asset Management US Inc. | 703,912 | $71.1M | 0.55% | +121,738+20.9% | Added |
| Jane Street Group, LLC | 707,441 | $72.3M | 0.08% | +707,441 | New |
| UBS Group AG | 801,430 | $81.9M | 0.01% | +5,522+0.7% | Added |
| American Century Companies Inc | 815,792 | $83.3M | 0.04% | +419,899+106.1% | Added |
| CIBC Bancorp USA Inc. | 828,793 | $84.6M | 0.11% | +828,793 | New |
| Pictet Asset Management Holding SA | 864,737 | $88.2M | 0.09% | −1,431,228−62.3% | Reduced |
| Swiss National Bank | 867,461 | $88.6M | 0.05% | +58,200+7.2% | Added |
| Mitsubishi UFJ Kokusai Asset Management Co., Ltd. | 908,365 | $92.8M | 0.06% | +68,799+8.2% | Added |
| Sumitomo Mitsui Trust Holdings, Inc. | 933,722 | $95.4M | 0.06% | +26,834+3.0% | Added |
| SEI Investments Co | 974,792 | $99.6M | 0.09% | −49,872−4.9% | Reduced |
| Amundi | 1,091,574 | $111.5M | 0.03% | −242,119−18.2% | Reduced |
| DekaBank Deutsche Girozentrale | 1,122,500 | $116.6M | 0.19% | 00.0% | Unchanged |
| Cbre Clarion Securities LLC | 1,237,915 | $126.4M | 1.87% | −208,682−14.4% | Reduced |
| HSBC Holdings PLC | 1,272,855 | $130.0M | 0.08% | +217,080+20.6% | Added |
| PGGM Investments | 1,369,998 | $139.9M | 2.45% | −287,161−17.3% | Reduced |
| Bank of America Corp | 1,399,375 | $142.9M | 0.01% | −110,970−7.3% | Reduced |
| Royal Bank of Canada | 1,410,720 | $144.1M | 0.03% | +124,849+9.7% | Added |
| Contour Asset Management LLC | 1,444,823 | $147.6M | 4.80% | −1,387,359−49.0% | Reduced |
| Russell Investments Group, Ltd. | 1,455,113 | $148.4M | 0.16% | +49,353+3.5% | Added |
| Duff & Phelps Investment Management Co | 1,575,337 | $160.9M | 1.67% | −5,115−0.3% | Reduced |
| Bank of New York Mellon Corp | 1,624,836 | $166.0M | 0.03% | −61,142−3.6% | Reduced |
| Vanguard Fiduciary Trust Co | 1,652,888 | $168.8M | 0.04% | +1,652,888 | New |
| AQR Capital Management LLC | 1,846,073 | $183.1M | 0.08% | +922,877+100.0% | Added |
| Ameriprise Financial Inc | 1,851,007 | $189.1M | 0.04% | +106,602+6.1% | Added |
| Capital World Investors | 1,867,169 | $190.7M | 0.03% | −250,000−11.8% | Reduced |
| JPMorgan Chase & Co | 2,123,358 | $207.2M | 0.01% | +195,423+10.1% | Added |
| Nuveen, LLC | 2,068,408 | $211.3M | 0.06% | −59,523−2.8% | Reduced |
| Vontobel Holding Ltd. | 2,116,877 | $216.2M | 0.74% | +427,631+25.3% | Added |
| Goldman Sachs Group Inc | 2,216,672 | $226.4M | 0.03% | +691,432+45.3% | Added |
| Centersquare Investment Management LLC | 2,310,045 | $235.9M | 2.44% | −321,408−12.2% | Reduced |
| Prudential Financial Inc | 2,416,063 | $246.8M | 0.30% | +105,582+4.6% | Added |
| Deutsche Bank AG | 3,092,084 | $315.8M | 0.10% | +550,092+21.6% | Added |
| Daiwa Securities Group Inc. | 3,107,440 | $317.4M | 0.92% | −546,646−15.0% | Reduced |
| Legal & General Group Plc | 3,135,074 | $320.2M | 0.07% | −221,346−6.6% | Reduced |
| Invesco Ltd. | 3,921,521 | $400.5M | 0.04% | −495,846−11.2% | Reduced |
| Charles Schwab Investment Management Inc | 4,013,007 | $409.9M | 0.06% | +132,732+3.4% | Added |
| Northern Trust Corp | 4,150,486 | $423.9M | 0.06% | −2,083−0.1% | Reduced |
| Dimensional Fund Advisors LP | 4,552,286 | $464.9M | 0.10% | +122,927+2.8% | Added |
| Principal Financial Group Inc | 4,566,093 | $466.4M | 0.25% | +358,497+8.5% | Added |
| Morgan Stanley | 4,652,247 | $475.2M | 0.03% | +1,053,274+29.3% | Added |
| FMR LLC | 7,484,398 | $764.5M | 0.04% | −499,906−6.3% | Reduced |
| Geode Capital Management, LLC | 8,486,127 | $863.7M | 0.05% | +193,474+2.3% | Added |
| Cohen & Steers, Inc. | 16,169,341 | $1.65B | 2.87% | −2,734,375−14.5% | Reduced |
| State Street Corp | 17,551,633 | $1.81B | 0.06% | +662,835+3.9% | Added |
| Vanguard Capital Management LLC | 18,758,889 | $1.92B | 0.05% | +18,758,889 | New |
| Vanguard Portfolio Management LLC | 25,015,557 | $2.56B | 0.13% | +25,015,557 | New |
| BlackRock, Inc. | 33,021,354 | $3.37B | 0.06% | +101,696+0.3% | Added |
| Verition Fund Management LLC | 0 | $0 | 0.00% | −208,951−100.0% | Sold out |
| SG Americas Securities, LLC | 0 | $0 | 0.00% | −137,582−100.0% | Sold out |
| Two Sigma Advisers, LP | 0 | $0 | 0.00% | −130,324−100.0% | Sold out |
| Canada Pension Plan Investment Board | 0 | $0 | 0.00% | −88,145−100.0% | Sold out |
| Polar Asset Management Partners Inc. | 0 | $0 | 0.00% | −86,400−100.0% | Sold out |
| Man Group plc | 0 | $0 | 0.00% | −57,346−100.0% | Sold out |
| Skandinaviska Enskilda Banken AB (publ) | 0 | $0 | 0.00% | −54,151−100.0% | Sold out |
| Sora Investors LLC | 0 | $0 | 0.00% | −47,345−100.0% | Sold out |
| Connor, Clark & Lunn Investment Management Ltd. | 0 | $0 | 0.00% | −39,394−100.0% | Sold out |
| Fieldview Capital Management, LLC | 0 | $0 | 0.00% | −36,518−100.0% | Sold out |