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 ($67.8m this quarter). Holder counts are more reliable. Shares outstanding: 295.8m as of 2026-02-06, 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 ≈ $82.98. Options: 19 managers hold calls ($114.7m notional), 18 hold puts ($63.0m).
Trends to Q4 2025
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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2024 | 420 | 399 |
| Q2 2024 | 421 | 436 |
| Q3 2024 | 467 | 481 |
| Q4 2024 | 441 | 517 |
| Q1 2025 | 424 | 545 |
| Q2 2025 | 502 | 416 |
| Q3 2025 | 436 | 481 |
| Q4 2025 | 396 | 515 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $150.7m | $172.9m | 1.15 |
| Q2 2025 | $103.1m | $151.7m | 1.47 |
| Q3 2025 | $103.9m | $100.8m | 0.97 |
| Q4 2025 | $114.7m | $63.0m | 0.55 |
Biggest buyers
| COHEN & STEERS, INC. | Added | +3.2m |
| PRINCIPAL FINANCIAL GROUP INC | Added | +1.7m |
| BlackRock, Inc. | Added | +1.2m |
| HSBC HOLDINGS PLC | Added | +1.2m |
| CITADEL ADVISORS LLC | Added | +1.1m |
| Vontobel Holding Ltd. | Added | +610.8k |
| Daiwa Securities Group Inc. | Added | +503.0k |
| AQR CAPITAL MANAGEMENT LLC | Added | +465.7k |
| TEACHER RETIREMENT SYSTEM OF TEXAS | Added | +295.3k |
| TWO SIGMA INVESTMENTS, LP | New | +290.2k |
Biggest sellers
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Reduced | -3.2m |
| JPMORGAN CHASE & CO | Reduced | -2.2m |
| ROYAL BANK OF CANADA | Reduced | -1.0m |
| Invesco Ltd. | Reduced | -649.1k |
| UBS Group AG | Reduced | -640.4k |
| VANGUARD GROUP INC | Reduced | -625.6k |
| CAPTRUST FINANCIAL ADVISORS | Reduced | -513.1k |
| Point72 Asset Management, L.P. | Reduced | -506.0k |
| BAMCO INC /NY/ | Sold out | -436.8k |
| DEUTSCHE BANK AG\ | Reduced | -348.5k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $27.7m334.5k shares |
| SOROS FUND MANAGEMENT LLC | New | $27.2m327.7k shares |
| CITADEL ADVISORS LLC | Added | $14.8m177.9k shares |
| Squarepoint Ops LLC | Added | $9.7m116.4k shares |
| IMC-Chicago, LLC | Added | $6.7m81.2k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $6.2m74.6k shares |
| CAPITAL FUND MANAGEMENT S.A. | Reduced | $5.9m70.9k shares |
| JANE STREET GROUP, LLC | Added | $3.7m45.0k shares |
| TUDOR INVESTMENT CORP ET AL | Added | $3.4m40.4k shares |
| D. E. Shaw & Co., Inc. | Added | $2.8m34.1k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $11.0m132.2k shares |
| PEAK6 LLC | New | $9.3m111.8k shares |
| Twin Tree Management, LP | Unchanged | $8.7m104.7k shares |
| Squarepoint Ops LLC | Added | $8.0m96.5k shares |
| CITADEL ADVISORS LLC | Reduced | $7.5m90.5k shares |
| CAPITAL FUND MANAGEMENT S.A. | Reduced | $5.6m67.5k shares |
| JANE STREET GROUP, LLC | Reduced | $2.5m30.0k shares |
| WOLVERINE ASSET MANAGEMENT LLC | Unchanged | $2.4m28.7k shares |
| TUDOR INVESTMENT CORP ET AL | Added | $1.8m21.2k shares |
| D. E. Shaw & Co., Inc. | New | $1.6m19.3k 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 in Q4 2025
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 |
|---|---|---|---|---|---|
| Q1 2024 | 0 | — | 6 | $26.3m | $26.3m |
| Q2 2024 | 0 | — | 10 | $14.6m | $14.3m |
| Q3 2024 | 0 | — | 5 | $12.9m | $11.2m |
| 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 |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-12-01 | Meaney William L President and CEO, director | Sold plan | $5.8m69.1k shares |
| 2025-12-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $510.0k6.0k shares |
| 2025-11-19 | Kelly Christie B. Director | Bought | $3.0k33 shares |
| 2025-11-03 | Meaney William L President and CEO, director | Sold plan | $7.1m69.1k shares |
| 2025-11-03 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $615.1k6.0k shares |
| 2025-10-31 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $736.6k7.3k shares |
| 2025-10-01 | Meaney William L President and CEO, director | Sold plan | $7.1m69.1k shares |
| 2025-10-01 | Kidd Mark EVP, GM Data Centers & ALM | Sold plan | $609.8k6.0k 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, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| VANGUARD GROUP INC 0.06% of their portfolio | 46.6m $3.9bn | Reduced -625.6k |
| BlackRock, Inc. 0.05% of their portfolio | 32.9m $2.7bn | Added +1.2m |
| COHEN & STEERS, INC. 2.83% of their portfolio | 18.9m $1.6bn | Added +3.2m |
| STATE STREET CORP 0.05% of their portfolio | 16.9m $1.4bn | Reduced -243.0k |
| GEODE CAPITAL MANAGEMENT, LLC 0.04% of their portfolio | 8.3m $685.4m | Added +102.1k |
| FMR LLC 0.03% of their portfolio | 8.0m $662.3m | Added +126.2k |
| NORGES BANK 0.04% of their portfolio | 4.4m $368.9m | Not comparable |
| DIMENSIONAL FUND ADVISORS LP 0.08% of their portfolio | 4.4m $367.4m | Added +81.3k |
| Invesco Ltd. 0.03% of their portfolio | 4.4m $366.4m | Reduced -649.1k |
| PRINCIPAL FINANCIAL GROUP INC 0.18% of their portfolio | 4.2m $349.0m | Added +1.7m |
| NORTHERN TRUST CORP 0.04% of their portfolio | 4.2m $344.5m | Added +121.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.05% of their portfolio | 3.9m $321.9m | Added +206.0k |
| Daiwa Securities Group Inc. 0.98% of their portfolio | 3.7m $303.1m | Added +503.0k |
| MORGAN STANLEY 0.02% of their portfolio | 3.6m $298.5m | Reduced -12.4k |
| Legal & General Group Plc 0.06% of their portfolio | 3.4m $278.4m | Added +141.0k |
| Contour Asset Management LLC 5.48% of their portfolio | 2.8m $234.9m | Reduced -333.6k |
| CENTERSQUARE INVESTMENT MANAGEMENT LLC 2.15% of their portfolio | 2.6m $218.3m | Added +117.0k |
| DEUTSCHE BANK AG\ 0.07% of their portfolio | 2.5m $210.9m | Reduced -348.5k |
| PRUDENTIAL FINANCIAL INC 0.23% of their portfolio | 2.3m $191.7m | Added +196.9k |
| Pictet Asset Management Holding SA 0.18% of their portfolio | 2.3m $190.4m | Reduced -168.2k |
| Nuveen, LLC 0.05% of their portfolio | 2.1m $176.5m | Reduced -14.6k |
| Capital World Investors 0.02% of their portfolio | 2.1m $175.6m | Unchanged |
| HSBC HOLDINGS PLC 0.05% of their portfolio | 2.1m $175.2m | Added +1.2m |
| JPMORGAN CHASE & CO 0.01% of their portfolio | 1.9m $159.9m | Reduced -2.2m |
| AMERIPRISE FINANCIAL INC 0.03% of their portfolio | 1.7m $142.5m | Added +38.4k |
| Vontobel Holding Ltd. 0.46% of their portfolio | 1.7m $140.1m | Added +610.8k |
| Bank of New York Mellon Corp 0.02% of their portfolio | 1.7m $139.9m | Added +19.4k |
| PGGM Investments 2.18% of their portfolio | 1.7m $137.5m | Reduced -27.6k |
| DUFF & PHELPS INVESTMENT MANAGEMENT CO 1.49% of their portfolio | 1.6m $131.1m | Reduced -61.6k |
| GOLDMAN SACHS GROUP INC 0.02% of their portfolio | 1.5m $126.5m | Added +171.1k |
| BANK OF AMERICA CORP /DE/ 0.01% of their portfolio | 1.5m $125.3m | Added +282.4k |
| CBRE INVESTMENT MANAGEMENT LISTED REAL ASSETS LLC 1.76% of their portfolio | 1.4m $120.0m | Added +177.1k |
| Russell Investments Group, Ltd. 0.13% of their portfolio | 1.4m $116.6m | Reduced -300.7k |
| Amundi 0.03% of their portfolio | 1.3m $110.6m | Added +248.4k |
| ROYAL BANK OF CANADA 0.02% of their portfolio | 1.3m $106.7m | Reduced -1.0m |
| DekaBank Deutsche Girozentrale 0.17% of their portfolio | 1.1m $95.8m | Unchanged |
| CITADEL ADVISORS LLC 0.06% of their portfolio | 1.1m $92.9m | Added +1.1m |
| SEI INVESTMENTS CO 0.08% of their portfolio | 1.0m $85.0m | Added +151.8k |
| AQR CAPITAL MANAGEMENT LLC 0.04% of their portfolio | 923.2k $76.6m | Added +465.7k |
| Sumitomo Mitsui Trust Group, Inc. 0.04% of their portfolio | 906.9k $75.2m | Reduced -27.9k |
| Mitsubishi UFJ Asset Management Co., Ltd. 0.05% of their portfolio | 839.6k $69.9m | Added +37.3k |
| Swiss National Bank 0.04% of their portfolio | 809.3k $67.1m | Reduced -41.3k |
| UBS Group AG 0.01% of their portfolio | 795.9k $66.0m | Reduced -640.4k |
| Point72 Asset Management, L.P. 0.10% of their portfolio | 790.5k $65.6m | Reduced -506.0k |
| BARCLAYS PLC 0.02% of their portfolio | 728.9k $60.5m | Reduced -11.0k |
| CIBC Private Wealth Group LLC 0.10% of their portfolio | 677.7k $56.2m | Reduced -43.4k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.08% of their portfolio | 656.9k $54.5m | Added +103.4k |
| Welch & Forbes LLC 0.66% of their portfolio | 656.4k $54.4m | Reduced -2.6k |
| WELLS FARGO & COMPANY/MN 0.01% of their portfolio | 637.3k $52.9m | Reduced -568 |
| LPL Financial LLC 0.01% of their portfolio | 634.8k $52.7m | Reduced -74.6k |
| Epoch Investment Partners, Inc. 0.30% of their portfolio | 629.9k $52.2m | Reduced -20.9k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.08% of their portfolio | 625.4k $52.0m | Added +127.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 606.9k $50.3m | Added +11.3k |
| RHUMBLINE ADVISERS 0.04% of their portfolio | 590.5k $49.0m | Reduced -6.1k |
| APG Asset Management US Inc. 0.38% of their portfolio | 582.2k $48.3m | Unchanged |
| BNP PARIBAS FINANCIAL MARKETS 0.03% of their portfolio | 562.3k $46.6m | Added +36.0k |
| Asset Management One Co., Ltd. 0.13% of their portfolio | 556.0k $45.9m | Added +4.3k |
| ALLIANCEBERNSTEIN L.P. 0.01% of their portfolio | 544.8k $45.2m | Reduced -11.2k |
| NOMURA ASSET MANAGEMENT CO LTD 0.11% of their portfolio | 544.5k $45.2m | Added +15.4k |
| California Public Employees Retirement System 0.02% of their portfolio | 513.6k $42.6m | Added +140 |
| National Pension Service 0.03% of their portfolio | 509.0k $42.2m | Added +13.5k |
| Border to Coast Pensions Partnership Ltd 0.72% of their portfolio | 500.0k $41.6m | Added +20.0k |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main 0.04% of their portfolio | 495.8k $41.1m | Reduced -19.2k |
| Heitman Real Estate Securities LLC 2.86% of their portfolio | 490.5k $40.7m | Added +16.2k |
| MILLENNIUM MANAGEMENT LLC 0.03% of their portfolio | 489.0k $40.6m | Added +3.6k |
| Corient Private Wealth LP 0.02% of their portfolio | 473.6k $35.1m | Added +271.1k |
| BANK OF MONTREAL /CAN/ 0.01% of their portfolio | 436.3k $36.2m | Added +38.2k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.04% of their portfolio | 434.1k $36.0m | Reduced -6.5k |
| NEUBERGER BERMAN GROUP LLC 0.03% of their portfolio | 431.4k $35.8m | Added +15.1k |
| STRS OHIO 0.13% of their portfolio | 414.1k $34.4m | Added +156.6k |
| Rockefeller Capital Management L.P. 0.06% of their portfolio | 404.0k $33.6m | Reduced -3.5k |
| AMERICAN CENTURY COMPANIES INC 0.02% of their portfolio | 395.9k $32.8m | Reduced -156.2k |
| RAYMOND JAMES FINANCIAL INC 0.01% of their portfolio | 366.3k $30.4m | Reduced -14.0k |
| Aberdeen Group plc 0.05% of their portfolio | 364.9k $30.3m | Reduced -17.7k |
| Adelante Capital Management LLC 1.90% of their portfolio | 339.2k $28.1m | Reduced -47.1k |
| CANADA LIFE ASSURANCE Co 0.05% of their portfolio | 336.9k $27.9m | Reduced -108.1k |
| TEACHER RETIREMENT SYSTEM OF TEXAS 0.10% of their portfolio | 334.0k $27.7m | Added +295.3k |
| CITIGROUP INC 0.02% of their portfolio | 318.6k $26.4m | Reduced -101.1k |
| ADELL HARRIMAN & CARPENTER INC 1.56% of their portfolio | 314.6k $26.1m | Reduced -11.7k |
| Marble Harbor Investment Counsel, LLC 2.78% of their portfolio | 314.0k $26.0m | Reduced -11.2k |
| MACQUARIE GROUP LTD 0.11% of their portfolio | 293.0k $24.3m | Added +6.4k |
| TWO SIGMA INVESTMENTS, LP 0.04% of their portfolio | 290.2k $24.1m | New |
| Swedbank AB 0.02% of their portfolio | 284.9k $23.6m | Unchanged |
| Apollo Management Holdings, L.P. 0.22% of their portfolio | 265.5k $22.0m | New |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.04% of their portfolio | 262.5k $21.8m | Reduced -8.2k |
| AVIVA PLC 0.04% of their portfolio | 256.1k $21.2m | Added +13.7k |
| CAPTRUST FINANCIAL ADVISORS 0.04% of their portfolio | 255.1k $21.2m | Reduced -513.1k |
| Cetera Investment Advisers 0.02% of their portfolio | 248.6k $20.6m | Reduced -5.8k |
| Americana Partners, LLC 0.55% of their portfolio | 241.3k $20.0m | New |
| BLAIR WILLIAM & CO/IL 0.05% of their portfolio | 238.3k $19.8m | Reduced -80.1k |
| Brookstone Capital Management 0.22% of their portfolio | 235.9k $19.6m | Added +28.5k |
| Retirement Systems of Alabama 0.06% of their portfolio | 228.1k $18.9m | Reduced -2.9k |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.04% of their portfolio | 227.9k $18.9m | Added +6 |
| STIFEL FINANCIAL CORP 0.02% of their portfolio | 227.2k $18.8m | Added +9.1k |
| Pacer Advisors, Inc. 0.05% of their portfolio | 223.4k $18.5m | Reduced -7.9k |
| Focus Partners Wealth 0.02% of their portfolio | 217.9k $18.3m | Added +88.3k |
| REGIONS FINANCIAL CORP 0.11% of their portfolio | 214.6k $17.8m | Reduced -288.9k |
| Schonfeld Strategic Advisors LLC 0.09% of their portfolio | 209.3k $17.4m | Added +111.1k |
| Verition Fund Management LLC 0.09% of their portfolio | 209.0k $17.3m | Added +181.1k |
| CIBC WORLD MARKET INC. 0.03% of their portfolio | 208.0k $17.3m | Added +35.6k |