IRON MTN INC DEL IRM
COM · REIT · CUSIP 46284V101 · ISIN US46284V1017
American information management company
- SectorReal estate
- IndustryReal Estate Investment Trusts
- HeadquartersPortsmouth, NH
- Founded1951
- Websiteironmountain.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($117.4m this quarter). Holder counts are more reliable. Shares outstanding: 297.7m as of 2026-07-24, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $126.18. Options: 23 managers hold calls ($171.6m notional), 21 hold puts ($343.0m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 743 |
| Q4 2022 | 781 |
| Q1 2023 | 790 |
| Q2 2023 | 817 |
| Q3 2023 | 833 |
| Q4 2023 | 892 |
| Q1 2024 | 938 |
| Q2 2024 | 966 |
| Q3 2024 | 1,055 |
| Q4 2024 | 1,066 |
| Q1 2025 | 995 |
| Q2 2025 | 1,045 |
| Q3 2025 | 1,017 |
| Q4 2025 | 1,011 |
| Q1 2026 | 1,089 |
| Q2 2026 | 1,167 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 467 | 481 |
| Q4 2024 | 441 | 517 |
| Q1 2025 | 424 | 545 |
| Q2 2025 | 502 | 416 |
| Q3 2025 | 436 | 481 |
| Q4 2025 | 396 | 515 |
| Q1 2026 | 559 | 442 |
| Q2 2026 | 588 | 440 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $103.9m | $100.8m | 0.97 |
| Q4 2025 | $114.7m | $63.0m | 0.55 |
| Q1 2026 | $139.4m | $258.8m | 1.86 |
| Q2 2026 | $171.6m | $343.0m | 2.00 |
Biggest buyers
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Added | +3.2m |
| GOLDMAN SACHS GROUP INC | Added | +606.1k |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Added | +553.4k |
| BlackRock, Inc. | Added | +549.6k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | New | +412.7k |
| FMR LLC | Added | +388.0k |
| AMERICAN CENTURY COMPANIES INC | Added | +338.7k |
| Aberdeen Group plc | Added | +320.3k |
| SG Americas Securities, LLC | New | +284.6k |
| Robeco Institutional Asset Management B.V. | Added | +283.3k |
Biggest sellers
| COHEN & STEERS, INC. | Reduced | -4.1m |
| Daiwa Securities Group Inc. | Reduced | -1.2m |
| PGGM Investments | Reduced | -694.9k |
| Capital World Investors | Reduced | -650.0k |
| Epoch Investment Partners, Inc. | Sold out | -616.5k |
| PRUDENTIAL FINANCIAL INC | Reduced | -442.0k |
| JANE STREET GROUP, LLC | Reduced | -310.9k |
| STRS OHIO | Sold out | -287.8k |
| BANK OF AMERICA CORP /DE/ | Reduced | -280.5k |
| SEI INVESTMENTS CO | Reduced | -277.1k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $44.0m348.5k shares |
| Caption Management, LLC | Added | $26.4m209.4k shares |
| IMC-Chicago, LLC | Added | $19.2m152.2k shares |
| CITADEL ADVISORS LLC | Reduced | $19.1m151.3k shares |
| JANE STREET GROUP, LLC | Added | $16.4m130.2k shares |
| Squarepoint Ops LLC | Added | $9.6m75.8k shares |
| ROYAL BANK OF CANADA | New | $7.6m60.0k shares |
| J. Goldman & Co LP | Added | $7.5m59.4k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $3.9m30.5k shares |
| NOMURA HOLDINGS INC | New | $3.6m28.2k shares |
Biggest puts
| Select Equity Group, L.P. | Reduced | $219.4m1.7m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $39.2m310.6k shares |
| CITADEL ADVISORS LLC | Added | $17.0m134.5k shares |
| IMC-Chicago, LLC | Added | $11.5m91.4k shares |
| WELLS FARGO & COMPANY/MN | New | $8.5m67.0k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $8.2m64.6k shares |
| GROUP ONE TRADING LLC | Reduced | $6.8m54.2k shares |
| JANE STREET GROUP, LLC | Reduced | $6.7m53.3k shares |
| ONTARIO TEACHERS PENSION PLAN BOARD | Unchanged | $6.1m48.3k shares |
| CAPTRUST FINANCIAL ADVISORS | Reduced | $3.4m27.1k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 8.4% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 7.3% |
Fell to 5% or below in the last year: COHEN & STEERS, INC. (4.9%, 2026-05-07), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 2 | $12.0m | $12.0m |
| Q1 2025 | 0 | — | 3 | $51.9m | $51.9m |
| Q2 2025 | 0 | — | 3 | $22.0m | $22.0m |
| Q3 2025 | 0 | — | 3 | $24.8m | $24.8m |
| Q4 2025 | 1 | $3.0k | 2 | $22.4m | $22.4m |
| Q1 2026 | 0 | — | 4 | $62.8m | $62.0m |
| Q2 2026 | 0 | — | 5 | $17.2m | $17.2m |
| Q3 2026 | 0 | — | 3 | $18.1m | $18.1m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-01 | Meaney William L President and CEO, director | Sold plan | $4.4m38.5k shares |
| 2026-09-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $693.6k6.0k shares |
| 2026-09-01 | McIntosh Greg W EVP, Chief Commercial Officer | Sold plan | $578.0k5.0k shares |
| 2026-08-07 | Meaney William L President and CEO, director | Sold plan | $4.7m38.5k shares |
| 2026-08-07 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $736.2k6.0k shares |
| 2026-08-06 | McIntosh Greg W EVP, Chief Commercial Officer | Sold plan | $1.5m11.8k shares |
| 2026-07-01 | Meaney William L President and CEO, director | Sold plan | $4.7m38.5k shares |
| 2026-07-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $753.7k6.0k shares |
| 2026-06-01 | Meaney William L President and CEO, director | Sold plan | $4.9m38.5k shares |
| 2026-06-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $760.2k6.0k shares |
| 2026-05-21 | Borges Daniel SVP & Chief Accounting Officer | Sold plan | $902.2k7.2k shares |
| 2026-05-20 | RAKOWICH WALTER C Director | Sold plan | $94.2k757 shares |
| 2026-05-12 | Arway Pamela M Director | Sold plan | $244.0k1.9k shares |
| 2026-05-08 | Meaney William L President and CEO, director | Sold plan | $5.0m38.5k shares |
| 2026-05-08 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $767.5k6.0k shares |
| 2026-04-01 | Meaney William L President and CEO, director | Sold plan | $4.0m38.5k shares |
| 2026-04-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $616.3k6.0k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.06% of their portfolio | 33.6m $4.2bn | Added +549.6k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.15% of their portfolio | 25.6m $3.2bn | Added +553.4k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 19.0m $2.4bn | Added +194.8k |
| STATE STREET CORP 0.07% of their portfolio | 17.6m $2.2bn | Added +82.4k |
| COHEN & STEERS, INC. 2.40% of their portfolio | 12.0m $1.5bn | Reduced -4.1m |
| GEODE CAPITAL MANAGEMENT, LLC 0.06% of their portfolio | 8.6m $1.1bn | Added +163.1k |
| FMR LLC 0.04% of their portfolio | 7.9m $994.4m | Added +388.0k |
| DIMENSIONAL FUND ADVISORS LP 0.11% of their portfolio | 4.6m $584.3m | Added +73.4k |
| MORGAN STANLEY 0.03% of their portfolio | 4.4m $559.2m | Reduced -225.3k |
| PRINCIPAL FINANCIAL GROUP INC 0.27% of their portfolio | 4.4m $552.4m | Reduced -192.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.07% of their portfolio | 4.3m $538.5m | Added +250.5k |
| NORTHERN TRUST CORP 0.06% of their portfolio | 4.2m $533.4m | Added +72.5k |
| NORGES BANK 0.05% of their portfolio | 4.2m $532.4m | Not comparable |
| Invesco Ltd. 0.04% of their portfolio | 4.1m $513.5m | Added +144.1k |
| Legal & General Group Plc 0.09% of their portfolio | 3.2m $409.8m | Added +109.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.07% of their portfolio | 3.2m $403.4m | Added +3.2m |
| DEUTSCHE BANK AG\ 0.11% of their portfolio | 3.0m $385.1m | Reduced -43.0k |
| GOLDMAN SACHS GROUP INC 0.04% of their portfolio | 2.8m $356.5m | Added +606.1k |
| CENTERSQUARE INVESTMENT MANAGEMENT LLC 2.51% of their portfolio | 2.3m $293.5m | Added +13.9k |
| Nuveen, LLC 0.07% of their portfolio | 2.2m $280.3m | Added +150.4k |
| JPMORGAN CHASE & CO 0.02% of their portfolio | 2.2m $287.5m | Added +88.8k |
| AQR CAPITAL MANAGEMENT LLC 0.09% of their portfolio | 2.1m $266.5m | Added +281.0k |
| PRUDENTIAL FINANCIAL INC 0.27% of their portfolio | 2.0m $249.3m | Reduced -442.0k |
| Vontobel Holding Ltd. 0.81% of their portfolio | 1.9m $242.5m | Reduced -197.2k |
| Daiwa Securities Group Inc. 0.53% of their portfolio | 1.9m $235.1m | Reduced -1.2m |
| AMERIPRISE FINANCIAL INC 0.04% of their portfolio | 1.7m $210.9m | Reduced -182.7k |
| VANGUARD FIDUCIARY TRUST CO 0.05% of their portfolio | 1.7m $209.5m | Added +5.7k |
| ROYAL BANK OF CANADA 0.04% of their portfolio | 1.6m $207.2m | Added +229.8k |
| Bank of New York Mellon Corp 0.03% of their portfolio | 1.6m $202.1m | Reduced -24.8k |
| DUFF & PHELPS INVESTMENT MANAGEMENT CO 1.73% of their portfolio | 1.5m $183.8m | Reduced -119.9k |
| Russell Investments Group, Ltd. 0.16% of their portfolio | 1.4m $177.4m | Reduced -51.5k |
| HSBC HOLDINGS PLC 0.08% of their portfolio | 1.3m $170.3m | Added +75.0k |
| Contour Asset Management LLC 3.81% of their portfolio | 1.3m $161.0m | Reduced -170.1k |
| Capital World Investors 0.02% of their portfolio | 1.2m $153.7m | Reduced -650.0k |
| Amundi 0.04% of their portfolio | 1.2m $147.6m | Added +76.9k |
| AMERICAN CENTURY COMPANIES INC 0.06% of their portfolio | 1.2m $145.8m | Added +338.7k |
| DekaBank Deutsche Girozentrale 0.19% of their portfolio | 1.1m $114.2m | Unchanged |
| BANK OF AMERICA CORP /DE/ 0.01% of their portfolio | 1.1m $141.3m | Reduced -280.5k |
| CBRE INVESTMENT MANAGEMENT LISTED REAL ASSETS LLC 1.89% of their portfolio | 1.1m $135.5m | Reduced -165.0k |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.07% of their portfolio | 982.6k $124.1m | Added +74.2k |
| UBS Group AG 0.02% of their portfolio | 915.1k $115.6m | Added +113.7k |
| Sumitomo Mitsui Trust Group, Inc. 0.06% of their portfolio | 896.6k $113.2m | Reduced -37.2k |
| Swiss National Bank 0.06% of their portfolio | 839.1k $106.0m | Reduced -28.4k |
| Pictet Asset Management Holding SA 0.10% of their portfolio | 817.6k $103.3m | Reduced -47.1k |
| CIBC Bancorp USA Inc. 0.12% of their portfolio | 777.5k $98.2m | Reduced -51.3k |
| BARCLAYS PLC 0.03% of their portfolio | 743.3k $93.9m | Added +69.6k |
| APG Asset Management US Inc. 0.60% of their portfolio | 703.9k $85.8m | Unchanged |
| SEI INVESTMENTS CO 0.08% of their portfolio | 697.7k $88.1m | Reduced -277.1k |
| Aberdeen Group plc 0.12% of their portfolio | 691.5k $87.3m | Added +320.3k |
| PGGM Investments 2.10% of their portfolio | 675.1k $85.3m | Reduced -694.9k |
| WELLS FARGO & COMPANY/MN 0.01% of their portfolio | 662.2k $83.6m | Added +3.7k |
| BNP PARIBAS FINANCIAL MARKETS 0.04% of their portfolio | 648.2k $81.9m | Added +139.7k |
| Vanguard Global Advisers, LLC 0.04% of their portfolio | 641.9k $81.1m | Reduced -5.9k |
| LPL Financial LLC 0.02% of their portfolio | 640.4k $80.9m | Added +19.1k |
| Welch & Forbes LLC 0.98% of their portfolio | 639.3k $80.8m | Reduced -12.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 634.6k $80.2m | Added +33.0k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.12% of their portfolio | 610.9k $77.1m | Added +20.4k |
| Quantinno Capital Management LP 0.09% of their portfolio | 590.6k $74.6m | Added +268.6k |
| NOMURA ASSET MANAGEMENT CO LTD 0.16% of their portfolio | 588.4k $74.3m | Added +25.0k |
| RHUMBLINE ADVISERS 0.05% of their portfolio | 573.3k $72.4m | Reduced -5.3k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.05% of their portfolio | 568.8k $71.9m | Added +63.9k |
| ALLIANCEBERNSTEIN L.P. 0.02% of their portfolio | 562.7k $57.5m | Reduced -2.5k |
| RAYMOND JAMES FINANCIAL INC 0.02% of their portfolio | 561.5k $70.9m | Added +266.4k |
| Asset Management One Co., Ltd. 0.18% of their portfolio | 554.6k $70.1m | Added +7.1k |
| California Public Employees Retirement System 0.04% of their portfolio | 553.9k $70.0m | Added +51.4k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.10% of their portfolio | 552.2k $69.7m | Reduced -34.7k |
| WORLDQUANT MILLENNIUM ADVISORS LLC 0.23% of their portfolio | 537.2k $67.8m | Reduced -10.9k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.09% of their portfolio | 535.2k $67.6m | Reduced -54.9k |
| WELLINGTON MANAGEMENT GROUP LLP 0.01% of their portfolio | 512.9k $64.8m | Added +165.0k |
| Clark Capital Management Group, Inc. 0.33% of their portfolio | 476.8k $60.2m | Added +8.4k |
| DigitalBridge Group, Inc. 3.47% of their portfolio | 457.1k $57.7m | Reduced -46.9k |
| National Pension Service 0.04% of their portfolio | 454.8k $57.4m | Added +25.4k |
| BANK OF MONTREAL /CAN/ 0.02% of their portfolio | 453.7k $57.3m | Added +47.7k |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND 0.08% of their portfolio | 443.9k $56.1m | Added +229.0k |
| VIRGINIA RETIREMENT SYSTEMS ET Al 0.33% of their portfolio | 441.8k $55.8m | Added +1.7k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.05% of their portfolio | 434.5k $54.9m | Added +11.7k |
| PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO 0.16% of their portfolio | 422.6k $53.4m | Reduced -1.1k |
| CITIGROUP INC 0.02% of their portfolio | 422.5k $53.4m | Added +106.9k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.22% of their portfolio | 412.7k $52.1m | New |
| JANE STREET GROUP, LLC 0.03% of their portfolio | 396.5k $50.1m | Reduced -310.9k |
| Rockefeller Capital Management L.P. 0.08% of their portfolio | 391.6k $49.5m | Added +2.5k |
| Heitman Real Estate Securities LLC 2.90% of their portfolio | 357.7k $45.2m | Added +98.1k |
| CANADA LIFE ASSURANCE Co 0.07% of their portfolio | 355.7k $44.8m | Added +19.8k |
| Vanguard Investments Australia, Ltd. 0.11% of their portfolio | 347.3k $43.9m | Added +4.0k |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 343.2k $43.3m | Reduced -31.8k |
| Adelante Capital Management LLC 2.70% of their portfolio | 325.6k $41.1m | Reduced -31.3k |
| ADELL HARRIMAN & CARPENTER INC 2.05% of their portfolio | 316.5k $40.0m | Added +648 |
| BAMCO INC /NY/ 0.06% of their portfolio | 310.7k $39.2m | Reduced -214.5k |
| Robeco Institutional Asset Management B.V. 0.05% of their portfolio | 297.9k $37.6m | Added +283.3k |
| TEACHER RETIREMENT SYSTEM OF TEXAS 0.10% of their portfolio | 297.4k $37.6m | Reduced -97.3k |
| Marble Harbor Investment Counsel, LLC 3.79% of their portfolio | 295.5k $37.3m | Reduced -4.9k |
| ACADIAN ASSET MANAGEMENT LLC 0.04% of their portfolio | 292.1k $36.9m | Added +123.2k |
| NEUBERGER BERMAN GROUP LLC 0.02% of their portfolio | 290.4k $36.7m | Reduced -70.4k |
| Swedbank AB 0.03% of their portfolio | 287.1k $36.3m | Added +26.7k |
| COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS 0.18% of their portfolio | 286.4k $36.2m | Added +84.1k |
| SG Americas Securities, LLC 0.02% of their portfolio | 284.6k $35.9m | New |
| MACQUARIE GROUP LTD 0.15% of their portfolio | 276.0k $34.9m | Added +5.4k |
| Border to Coast Pensions Partnership Ltd 0.51% of their portfolio | 275.0k $34.7m | Reduced -195.0k |
| VICTORY CAPITAL MANAGEMENT INC 0.02% of their portfolio | 268.2k $33.9m | Added +30.0k |
| Apollo Management Holdings, L.P. 0.47% of their portfolio | 265.5k $33.5m | Unchanged |