Iron MountainIRM
13F holders, Q3 2025 (September 30)1,016holders −28
67new positions
87sold out
8famous investors
$101.97avg. 13F price*
At the end of Q3 2025, 1,016 institutions reported holding Iron Mountain Inc. (IRM) in their 13F filings, down 28 from Q2 2025. 67 opened new positions and 87 sold out. The largest holders were Vanguard Group Inc. ($4.8B), BlackRock, Inc. ($3.2B) and State Street Corp. ($1.8B). 8 famous investors held it, including Steve Cohen (0.3% of Point72 Asset Management's portfolio), Ron Baron (0.1% of Baron Capital (BAMCO)'s portfolio) and Israel Englander (0.0% of Millennium Management's portfolio).
- Company
- Iron Mountain Inc.
- Filed as
- IRON MTN INC DEL (Q3 2025)
- Sector
- Real Estate
- CUSIP
- 46284V101
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q2 2025 → Q3 2025
| Institutions | Total Value | |
|---|---|---|
| New Positions | 67 | $150.1M |
| Exits | 87 | $227.6M |
All 13F filers, Q2 2025 → Q3 2025: 15,792,936 shares bought and 10,298,045 shares sold, net +5,494,891 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 1,016 holders
| Vanguard Group Inc. | 0.07% | Add +0.4% | 47,253,100 | $4.8B |
| BlackRock, Inc. | 0.06% | Add +1.4% | 31,709,064 | $3.2B |
| State Street Corp. | 0.06% | Add +1.9% | 17,131,787 | $1.8B |
| Cohen & Steers, Inc. | 2.90% | Add +14.4% | 15,748,682 | $1.6B |
| Geode Capital Management, LLC | 0.05% | Add +1.3% | 8,190,580 | $831.7M |
| FMR LLC | 0.04% | Add +17.3% | 7,858,092 | $801.1M |
| Invesco Ltd. | 0.08% | Add +18.1% | 5,066,516 | $516.5M |
| Dimensional Fund Advisors LP | 0.10% | Add +1.3% | 4,348,039 | $443.2M |
| Northern Trust Corp. | 0.05% | Reduce -0.9% | 4,031,566 | $411.0M |
| Charles Schwab Investment Management Inc. | 0.06% | Add +1.3% | 3,674,245 | $374.6M |
| Morgan Stanley | 0.02% | Add +3.0% | 3,611,399 | $368.1M |
| Legal & General Group Plc | 0.07% | Reduce -2.1% | 3,215,455 | $327.8M |
| Contour Asset Management LLC | 8.09% | Add +35.6% | 3,165,830 | $322.7M |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 0.07% | Add +597.9% | 3,161,589 | $322.3M |
| Daiwa Securities Group Inc. | 1.09% | Add +6.6% | 3,151,088 | $321.2M |
| Deutsche Bank AG | 0.10% | Reduce -15.7% | 2,890,451 | $294.7M |
| Principal Financial Group Inc. | 0.13% | Reduce -2.2% | 2,527,158 | $257.6M |
| Centersquare Investment Management LLC | 2.58% | Add +23.8% | 2,514,464 | $256.3M |
| Pictet Asset Management Holding SA | 0.24% | Reduce -0.5% | 2,464,168 | $251.1M |
| Royal Bank of Canada | 0.04% | Add +12.5% | 2,298,983 | $234.4M |
| Nuveen, LLC | 0.06% | Add +4.3% | 2,142,505 | $218.4M |
| Capital World Investors | 0.03% | No change | 2,117,169 | $215.8M |
| Prudential Financial Inc. | 0.26% | Add +8.6% | 2,113,617 | $215.5M |
| JPMorgan Chase & Co. | 0.01% | Add +4.2% | 2,056,448 | $209.6M |
| Russell Investments Group, Ltd. | 0.20% | Reduce -6.4% | 1,706,435 | $173.9M |
| Ameriprise Financial Inc. | 0.04% | Add +0.0% | 1,706,032 | $173.8M |
| PGGM Investments | 2.78% | Add +7.6% | 1,684,781 | $171.7M |
| Bank of New York Mellon Corp | 0.03% | Reduce -4.6% | 1,666,560 | $169.9M |
| Duff & Phelps Investment Management Co. | 1.90% | Add +11.5% | 1,642,074 | $167.4M |
| UBS Group AG | 0.03% | Reduce -20.2% | 1,436,301 | $146.4M |
| Goldman Sachs Group Inc. | 0.02% | Reduce -28.0% | 1,354,097 | $138.0M |
| Point72 Asset Management | 0.31% | Add +27.8% | 1,296,531 | $132.2M |
| CBRE Investment Management Listed Real Assets LLC | 1.85% | Add +18.3% | 1,269,467 | $129.4M |
| Bank of America Corp. | 0.01% | Reduce -1.7% | 1,227,950 | $125.2M |
| Amundi | 0.04% | Reduce -32.2% | 1,085,307 | $115.4M |
| DekaBank Deutsche Girozentrale | 0.19% | No change | 1,122,500 | $112.3M |
| Vontobel Holding Ltd. | 0.35% | New | 1,078,487 | $109.9M |
| HSBC Holdings PLC | 0.06% | Add +21.3% | 951,576 | $96.9M |
| Sumitomo Mitsui Trust Group, Inc. | 0.05% | Add +1.1% | 934,752 | $95.3M |
| Sei Investments Co. | 0.10% | Reduce -1.4% | 872,870 | $89.0M |
| Swiss National Bank | 0.05% | Reduce -4.3% | 850,561 | $86.7M |
| Mitsubishi UFJ Asset Management Co., Ltd. | 0.06% | Add +4.7% | 802,312 | $81.8M |
| Captrust Financial Advisors | 0.16% | Reduce -0.1% | 768,266 | $78.3M |
| Barclays PLC | 0.03% | Add +36.1% | 739,890 | $75.4M |
| CIBC Private Wealth Group LLC | 0.13% | Reduce -1.7% | 721,087 | $73.5M |
| LPL Financial LLC | 0.02% | Add +5.3% | 709,400 | $72.3M |
| Welch & Forbes LLC | 0.81% | Reduce -1.5% | 658,992 | $67.2M |
| Epoch Investment Partners, Inc. | 0.36% | Reduce -4.8% | 650,757 | $66.3M |
| Wells Fargo & Company | 0.01% | Add +2.0% | 637,840 | $65.0M |
| Rhumbline Advisers | 0.05% | Reduce -3.8% | 596,637 | $60.8M |
| T. Rowe Price Associates Inc. | 0.01% | Reduce -5.0% | 595,595 | $60.7M |
| APG Asset Management US Inc. | 0.44% | No change | 582,174 | $59.5M |
| Alliancebernstein L.P. | 0.02% | Reduce -0.9% | 555,994 | $56.7M |
| Adage Capital Partners Gp, L.L.C. | 0.09% | Reduce -1.2% | 553,420 | $56.4M |
| American Century Companies Inc. | 0.03% | Reduce -25.9% | 552,049 | $56.3M |
| Asset Management One Co., Ltd. | 0.16% | Reduce -0.8% | 551,714 | $56.2M |
| Nomura Asset Management Co. Ltd. | 0.14% | Add +2.2% | 529,048 | $53.9M |
| BNP Paribas Financial Markets | 0.04% | Add +23.4% | 526,270 | $53.6M |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main | 0.05% | Add +36.3% | 515,006 | $52.5M |
| California Public Employees Retirement System | 0.03% | Add +4.0% | 513,415 | $52.3M |
| Universal- Beteiligungs- und Servicegesellschaft mbH | 0.09% | Add +4.1% | 497,720 | $50.7M |
| National Pension Service | 0.04% | Add +4.1% | 495,480 | $50.5M |
| Millennium Management | 0.04% | Reduce -15.7% | 485,417 | $49.5M |
| Border to Coast Pensions Partnership Ltd | 0.85% | No change | 480,000 | $48.9M |
| Heitman Real Estate Securities LLC | 3.30% | Add +2.3% | 474,368 | $48.4M |
| AQR Capital Management | 0.03% | Add +331.5% | 457,472 | $46.4M |
| California State Teachers Retirement System | 0.05% | Reduce -2.6% | 440,557 | $44.9M |
| CANADA LIFE ASSURANCE Co | 0.06% | Add +1.7% | 445,064 | $44.7M |
| Baron Capital (BAMCO) | 0.12% | Add +306.3% | 436,831 | $44.5M |
| Citigroup Inc. | 0.03% | Add +105.3% | 419,723 | $42.8M |
| Neuberger Berman Group LLC | 0.03% | Add +14.2% | 416,248 | $42.4M |
| Rockefeller Capital Management L.P. | 0.08% | Add +7.5% | 407,455 | $41.6M |
| Bank of Montreal | 0.02% | Add +8.7% | 398,180 | $40.6M |
| Adelante Capital Management LLC | 2.63% | Reduce -4.2% | 386,285 | $39.4M |
| Raymond James Financial Inc. | 0.01% | Reduce -3.2% | 380,348 | $38.8M |
| Aberdeen Group plc | 0.06% | Add +12.7% | 382,634 | $38.4M |
| Adell Harriman & Carpenter Inc. | 2.02% | Add +0.6% | 326,315 | $33.3M |
| Marble Harbor Investment Counsel, LLC | 3.47% | Reduce -1.1% | 325,260 | $33.2M |
| Blair William & Co. | 0.09% | Add +1.4% | 318,410 | $32.5M |
| Aew Capital Management L P | 1.79% | Reduce -49.1% | 315,257 | $32.1M |
| KBC Group NV | 0.07% | Add +345.3% | 292,478 | $29.8M |
| Gillson Capital LP | 2.54% | Reduce -22.3% | 286,900 | $29.2M |
| Macquarie Group Ltd. | 0.03% | Reduce -0.8% | 286,584 | $29.2M |
| Swedbank AB | 0.03% | Reduce -9.6% | 284,858 | $29.0M |
| State Board of Administration of Florida Retirement System | 0.05% | Reduce -8.5% | 270,757 | $27.6M |
| STRS Ohio | 0.10% | Add +14.7% | 257,515 | $26.3M |
| Cetera Investment Advisers | 0.03% | Add +50.1% | 254,352 | $25.9M |
| Regions Financial Corp. | 0.17% | Add +1.4% | 251,781 | $25.7M |
| Wellington Management Group LLP | 0.00% | Reduce -83.3% | 248,892 | $25.4M |
| Aviva PLC | 0.04% | Add +6.2% | 242,449 | $24.7M |
| Pacer Advisors, Inc. | 0.06% | Add +5.0% | 231,235 | $23.6M |
| Retirement Systems of Alabama | 0.08% | Reduce -0.1% | 230,939 | $23.5M |
| Worldquant Millennium Advisors LLC | 0.10% | Reduce -13.9% | 230,912 | $23.5M |
| New York State Teachers Retirement System | 0.05% | Reduce -0.0% | 227,870 | $23.2M |
| Victory Capital Management Inc. | 0.01% | Reduce -3.9% | 222,934 | $22.7M |
| Stifel Financial Corp. | 0.02% | Add +1.4% | 218,137 | $22.2M |
| Andra AP-fonden | 0.28% | Reduce -12.3% | 215,700 | $22.0M |
| Canada Pension Plan Investment Board | 0.02% | Add +94.8% | 210,283 | $21.4M |
| Brookstone Capital Management | 0.25% | Add +40.1% | 207,443 | $21.1M |
| National Bank of Canada | 0.02% | Reduce -10.4% | 203,663 | $20.8M |
"% of holder's portfolio" is IRM's weight in each manager's 13F, not the share of Iron Mountain Inc. the manager owns.