SEC ownership of IRON MOUNTAIN INC

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001020569.

Comparable stake leader

VANGUARD PORTFOLIO MANAGEMENT LLC

Disclosed value leader

BlackRock, Inc.

Comparable rows

50/50

Latest evidence

07 Aug 2026

Top shareholders Insider holders Latest transactions
Public ticker
IRM on NYSE
Parsed ownership sources
13F, 13D/G, 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
Ownership snapshot CIK-linked ownership evidence from parsed SEC filings. 3 signals
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
07 Aug 2026
Freshness: Most recent filing date in this holder set
Issuer Names, identifiers, and filing context for this profile. 2 identity fields
Issuer CIK
0001020569
Issuer location
Portsmouth, NH

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
07 Aug 2026
13F 13D/G 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
13F 13D/G
Company · Vanguard Portfolio Management
13F 13D/G
8.4%
from 13D/G
$3,229,613,316
25,568,944 shares
 — 30 Jun 2026
VANGUARD CAPITAL MANAGEMENT LLC
13F 13D/G
Company · Vanguard Capital Management
13F 13D/G
7.4%
from 13D/G
$2,394,042,478
18,953,705 shares
 — 30 Jun 2026
COHEN & STEERS, INC.
13F 13D/G
Company
13F 13D/G
4.9%
from 13D/G
$1,518,214,000
12,019,735 shares
 — 30 Jun 2026
Kent P. Dauten
3/4/5
Director
3/4/5
0.41%
$123,545,786
1,209,573 shares
 — 07 May 2026
Barry A. Hytinen
3/4/5
EVP and CFO
3/4/5
0.11%
$35,383,069
326,623 shares
 — 01 Mar 2026
Clark H. Bailey
3/4/5
Director
3/4/5
0.09%
$33,317,345
254,864 shares
mixed-class rows
 — 01 Jul 2025
Mark Kidd
3/4/5
EVP, GM Data Centers & ALM
3/4/5
0.03%
$12,454,908
101,507 shares
 -$7,896,511 07 Aug 2026
Greg W. McIntosh
3/4/5
EVP, Chief Commercial Officer
3/4/5
0.03%
$10,251,000
80,634 shares
 -$1,505,092 06 Aug 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: -$121,529,524.

Buys
$2,954
Insiders: 1
Sells
$121,532,478
Insiders: 8
Net
-$121,529,524
Shares: -1,146,609
Window
Last 12 months
4 rolling buckets
Buy value Sell value
Shares: 33 Shares: 1,146,642
Window (months) Buy shares Sell shares Buy value Sell value Net value
0-3 0 100,787 $0 $12,401,795 -$12,401,795
3-6 0 498,960 $0 $55,067,185 -$55,067,185
6-9 0 239,089 $0 $24,917,303 -$24,917,303
9-12 33 307,806 $2,954 $29,146,195 -$29,143,241

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
-$120,983,225
Latest report
07 Aug 2026
Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
Kent P. Dauten Director $123,545,786 Mixed 07 May 2026
William L. Meaney President and CEO, Director $39,872,695 -$103,333,737 -72% Mixed 07 Aug 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
Mark Kidd EVP, GM Data Centers & ALM $12,454,908 -$7,896,511 -39% Filing P/S 07 Aug 2026
Greg W. McIntosh EVP, Chief Commercial Officer $10,251,000 -$1,505,092 -13% Filing P/S 06 Aug 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
Mark Kidd IRM Common Stock, par value $.01 per share Sale -5.58% $736,200 $122.70 -6,000 101,507 07 Aug 2026 Direct
William L. Meaney IRM Common Stock, par value $.01 per share Sale -100% $4,680,954 $121.67 -38,474 0 07 Aug 2026 Direct
William L. Meaney IRM Common Stock, par value $.01 per share Options Exercise 38,474 38,474 07 Aug 2026 Direct
William L. Meaney IRM Employee Stock Option (Right to Buy) Options Exercise -20% -38,474 153,896 07 Aug 2026 Direct
Greg W. McIntosh IRM Common Stock, par value $.01 per share Options Exercise 8.48% 6,839 87,473 06 Aug 2026 Direct
Greg W. McIntosh IRM Common Stock, par value $.01 per share Sale -12.8% $1,505,092 $127.13 -11,839 80,634 06 Aug 2026 Direct
Greg W. McIntosh IRM Employee Stock Option (Right to Buy) Options Exercise -100% -6,839 0 06 Aug 2026 Direct
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
* marks a reported price that did not pass the local price check.
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