Comparable stake leader
VANGUARD PORTFOLIO MANAGEMENT LLC
SEC ownership of IRON MOUNTAIN INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001020569.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
01 Jul 2026
- Public ticker
- IRM on NYSE
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
VANGUARD PORTFOLIO MANAGEMENT LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
VANGUARD PORTFOLIO MANAGEMENT LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
01 Jul 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001020569
- Issuer location
- Portsmouth, NH
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of IRON MOUNTAIN INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
VANGUARD PORTFOLIO MANAGE...
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
01 Jul 2026
13D/G
13F
3/4/5
Lead comparable stake: 8.4%
13D/G row: VANGUARD PORTFOLIO MANAGEMENT LLC
Showing 1-8 of 50 holder rows.
Quick read
VANGUARD PORTFOLIO MANAGEMENT LLC leads the comparable SEC ownership view at 8.4%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens VANGUARD PORTFOLIO MANAGEMENT LLC's linked filing trail.
Comparable ownership
Top 5
VANGUARD PORTFOLIO MANAGEMENT LLC
8.4%
VANGUARD CAPITAL MANAGEMENT LLC
7.4%
COHEN & STEERS, INC.
4.9%
Kent P. Dauten
0.41%
Barry A. Hytinen
0.11%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
8.4%
|
$2,558,722,929
25,051,135 shares
|
$0 | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
7.4%
|
$2,234,037,028
21,872,303 shares
|
$0 | 31 Mar 2026 |
| COHEN & STEERS, INC. |
13F
13D/G
Company
|
4.9%
from 13D/G
|
$1,651,537,000
16,169,341 shares
|
— | 31 Mar 2026 |
| Kent P. Dauten |
3/4/5
Director
|
0.41%
|
$123,545,786
1,209,573 shares
|
— | 07 May 2026 |
| Barry A. Hytinen |
3/4/5
EVP and CFO
|
0.11%
|
$35,383,069
326,623 shares
|
— | 01 Mar 2026 |
| Clark H. Bailey |
3/4/5
Director
|
0.09%
|
$33,317,345
254,864 shares
mixed-class rows
|
— | 01 Jul 2025 |
| Mark Kidd |
3/4/5
EVP, GM Data Centers & ALM
|
0.04%
|
$13,505,029
107,507 shares
|
-$7,706,611 | 01 Jul 2026 |
| Greg W. McIntosh |
3/4/5
EVP, Chief Commercial Officer
|
0.03%
|
$9,276,731
85,634 shares
|
— | 01 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$114,607,278.
Buys
$2,954
Insiders: 1
Sells
$114,610,232
Insiders: 7
Net
-$114,607,278
Shares: -1,090,296
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 33
Shares: 1,090,329
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 143,260 | $0 | $18,115,672 | -$18,115,672 |
| 3-6 | 0 | 594,781 | $0 | $63,649,161 | -$63,649,161 |
| 6-9 | 33 | 119,607 | $2,954 | $9,969,859 | -$9,966,905 |
| 9-12 | 0 | 232,681 | $0 | $22,875,540 | -$22,875,540 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 29 reporting-owner rows connected to IRON MOUNTAIN INC. Open a relationship link for the CIK-to-CIK filing trail.
Rows
29
Largest Forms 3/4/5 holder
Kent P. Dauten
Net 12M change
-$114,607,278
Latest report
06 Jul 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Kent P. Dauten | Director | $123,545,786 | Mixed | 07 May 2026 | ||
| Barry A. Hytinen | EVP and CFO | $35,383,069 | Mixed | 01 Mar 2026 | ||
| Clark H. Bailey | Director | $33,317,345 | Mixed | 01 Jul 2025 | ||
| William L. Meaney | President and CEO, Director | $32,726,835 | -$98,652,782 | -75% | Mixed | 01 Jul 2026 |
| Mark Kidd | EVP, GM Data Centers & ALM | $13,505,029 | -$7,706,611 | -36% | Filing P/S | 01 Jul 2026 |
| Greg W. McIntosh | EVP, Chief Commercial Officer | $9,276,731 | Mixed | 01 Mar 2026 | ||
| Deborah Marson | EVP, General Counsel, Sec. | $7,082,889 | Mixed | 03 Sep 2024 | ||
| Pamela M. Arway | Director | $5,184,078 | -$244,011 | -4.5% | Filing P/S | 12 May 2026 |
| Deirdre Evens | EVP & GM, Asset Lifestyle Mgmt | $5,173,496 | Mixed | 29 Mar 2022 | ||
| Ernest W. Cloutier | Evp & Gm, Rim | $5,045,767 | Mixed | 24 May 2021 | ||
| Doyle Simons | Director | $4,932,025 | Mixed | 06 Jul 2026 | ||
| Alfred J. Verrecchia | Director | $4,915,591 | Mixed | 05 Apr 2023 | ||
| Monte E. Ford | Director | $3,249,788 | Mixed | 07 May 2026 | ||
| Robin Matlock | Director | $3,111,146 | Mixed | 07 May 2026 | ||
| Kris Halvorsen | Director | $2,642,309 | Mixed | 04 Jan 2022 | ||
| Walter C. Rakowich | Director | $2,578,821 | -$94,209 | -3.5% | Mixed | 20 May 2026 |
| Mithu Bhargava | EVP, GM Digital Business Unit | $2,457,714 | -$6,248,239 | -72% | Mixed | 19 Mar 2026 |
| Wendy J. Murdock | Director | $1,725,799 | Filing P/S | 17 Sep 2024 | ||
| John Tomovcsik | EVP, Chief Operating Officer | $1,540,000 | Filing P/S | 19 Aug 2024 | ||
| Jennifer Allerton | Director | $1,358,462 | -$762,160 | -36% | Mixed | 07 May 2026 |
Recent insider transactions for IRON MOUNTAIN INC
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Doyle Simons | IRM | Phantom Stock | Award | 0.74% | 339 | 46,213 | 06 Jul 2026 | Direct | ||
| Theodore R. Samuels II | IRM | Phantom Stock | Award | 0.72% | 99.06 | 13,800 | 06 Jul 2026 | Direct | ||
| Theodore R. Samuels II | IRM | Phantom Stock | Award | 2.32% | 311 | 13,701 | 02 Jul 2026 | Direct | ||
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -100% | $4,725,829 | $122.83 | -38,474 | 0 | 01 Jul 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 38,474 | 38,474 | 01 Jul 2026 | Direct | |||
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Options Exercise | -16.7% | -38,474 | 192,370 | 01 Jul 2026 | Direct | ||
| Mark Kidd | IRM | Common Stock, par value $.01 per share | Sale | -5.29% | $753,720 | $125.62 | -6,000 | 107,507 | 01 Jul 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -100% | $4,907,535 | $127.55 | -38,474 | 0 | 01 Jun 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 38,474 | 38,474 | 01 Jun 2026 | Direct | |||
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Options Exercise | -14.3% | -38,474 | 230,844 | 01 Jun 2026 | Direct | ||
| Mark Kidd | IRM | Common Stock, par value $.01 per share | Sale | -5.02% | $760,200 | $126.70 | -6,000 | 113,507 | 01 Jun 2026 | Direct |
| Daniel Borges | IRM | Common Stock, par value $.01 per share | Sale | -100% | $902,220 | $125.50 | -7,189 | 0 | 21 May 2026 | Direct |
| Walter C. Rakowich | IRM | Common Stock, par value $.01 per share | Sale | -40% | $94,209 | $124.45 | -757 | 1,135 | 20 May 2026 | Direct |
| Pamela M. Arway | IRM | Common Stock, par value $.01 per share | Sale | -4.5% | $244,011 | $128.97 | -1,892 | 40,196 | 12 May 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -100% | $4,960,489 | $128.93 | -38,474 | 0 | 08 May 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 38,474 | 38,474 | 08 May 2026 | Direct | |||
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Options Exercise | -12.5% | -38,474 | 269,318 | 08 May 2026 | Direct | ||
| Mark Kidd | IRM | Common Stock, par value $.01 per share | Sale | -4.78% | $767,460 | $127.91 | -6,000 | 119,507 | 08 May 2026 | Direct |
| Theodore R. Samuels II | IRM | Phantom Stock | Award | 16.4% | 1,892 | 13,390 | 07 May 2026 | Direct | ||
| Monte E. Ford | IRM | Common Stock, par value $.01 per share | Award | 6.32% | 1,892 | 31,817 | 07 May 2026 | Direct | ||
| June Yee Felix | IRM | Common Stock, par value $.01 per share | Award | 63.3% | 1,892 | 4,883 | 07 May 2026 | Direct | ||
| Kent P. Dauten | IRM | Common Stock, par value $.01 per share | Award | 0.16% | 1,892 | 1,209,573 | 07 May 2026 | Direct | ||
| Robin Matlock | IRM | Common Stock, par value $.01 per share | Award | 6.62% | 1,892 | 30,451 | 07 May 2026 | Direct | ||
| Doyle Simons | IRM | Common Stock, par value $.01 per share | Award | 1,892 | 1,892 | 07 May 2026 | Direct | |||
| Walter C. Rakowich | IRM | Common Stock, par value $.01 per share | Award | 1,892 | 1,892 | 07 May 2026 | Direct | |||
| Christie B. Kelly | IRM | Common Stock, par value $.01 per share | Award | 143.4% | 1,892 | 3,211 | 07 May 2026 | Direct | ||
| Jennifer Allerton | IRM | Common Stock, par value $.01 per share | Tax liability | -0.99% | -133 | 13,300 | 07 May 2026 | Direct | ||
| Jennifer Allerton | IRM | Common Stock, par value $.01 per share | Award | 16.4% | 1,892 | 13,433 | 07 May 2026 | Direct | ||
| Pamela M. Arway | IRM | Common Stock, par value $.01 per share | Award | 4.71% | 1,892 | 42,088 | 07 May 2026 | Direct | ||
| Walter C. Rakowich | IRM | Common Stock, par value $.01 per share | Gift | -6.28% | -1,600 | 23,865 | 01 May 2026 | By Rakowich Living Trust | ||
| Doyle Simons | IRM | Phantom Stock | Award | 0.83% | 380 | 45,874 | 06 Apr 2026 | Direct | ||
| Theodore R. Samuels II | IRM | Phantom Stock | Award | 4% | 442 | 11,498 | 06 Apr 2026 | Direct | ||
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -100% | $3,951,665 | $102.71 | -38,474 | 0 | 01 Apr 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 38,474 | 38,474 | 01 Apr 2026 | Direct | |||
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Options Exercise | -11.1% | -38,474 | 307,792 | 01 Apr 2026 | Direct | ||
| Mark Kidd | IRM | Common Stock, par value $.01 per share | Sale | -4.56% | $616,260 | $102.71 | -6,000 | 125,507 | 01 Apr 2026 | Direct |
| Mithu Bhargava | IRM | Common Stock, par value $.01 per share | Sale | -78.8% | $6,248,239 | $104.62 | -59,725 | 16,054 | 19 Mar 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -100% | $10,482,131 | $106.25 | -98,657 | 0 | 05 Mar 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -50% | $10,592,310 | $107.36 | -98,659 | 98,657 | 04 Mar 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -33.3% | $10,540,456 | $106.84 | -98,659 | 197,316 | 03 Mar 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 13% | 38,474 | 334,449 | 02 Mar 2026 | Direct | ||
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Sale | -31.7% | $15,001,567 | $109.39 | -137,133 | 295,975 | 02 Mar 2026 | Direct |
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Options Exercise | -10% | -38,474 | 346,266 | 02 Mar 2026 | Direct | ||
| Mark Kidd | IRM | Common Stock, par value $.01 per share | Sale | -4.36% | $643,620 | $107.27 | -6,000 | 131,507 | 02 Mar 2026 | Direct |
| Jennifer Allerton | IRM | Common Stock, par value $.01 per share | Sale | -37.8% | $762,160 | $108.88 | -7,000 | 11,541 | 02 Mar 2026 | Direct |
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Tax liability | -39.4% | -256,040 | 394,634 | 01 Mar 2026 | Direct | ||
| William L. Meaney | IRM | Common Stock, par value $.01 per share | Options Exercise | 650,674 | 650,674 | 01 Mar 2026 | Direct | |||
| William L. Meaney | IRM | Employee Stock Option (Right to Buy) | Award | 74,069 | 74,069 | 01 Mar 2026 | Direct | |||
| William L. Meaney | IRM | Performance Units | Options Exercise | -100% | -650,674 | 0 | 01 Mar 2026 | Direct | ||
| Michelle Vervais Altamura | IRM | Common Stock, par value $.01 per share | Tax liability | -12.8% | -987 | 6,724 | 01 Mar 2026 | Direct |
* marks a reported price that did not pass the local price check.