Latest Period
Q2 2026
Security Snapshot
IRON MOUNTAIN INC - Common Stock (IRM) Institutional Ownership
CUSIP: 46284V101
13F Institutional Holders and Ownership History from Q1 2014 to Q2 2026
Institutions Reporting
1,161
Shares (Excl. Options)
256,148,405
Price
$126.31
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- Security type / class
- Equity / Common Stock
- Symbol
- IRM on NYSE
- All holders as of 30 Jun 2026
- Q2 2026
- Total 13F shares
- 256,148,405
- Total 13F value
- $32,321,498,331
- Portfolio coverage rank
- 0.02%
- Share change
- +3,580,573
- Value change
- +$492,521,445
- Number of holders
- 1,161
- Shares outstanding
- 297,661,125
- SEC-reported price per share
- $123.52
- Insider filing price
- $123.52
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- IRM - IRON MOUNTAIN INC - Common Stock is tracked under CUSIP 46284V101.
- 1161 institutions reported positions in Q2 2026.
- 3 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 1,086 to 1,161 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $25,805,946,586 to $32,321,498,331.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 1161 institutions filings for Q2 2026.
Security key
46284V101
Latest holder period
Q2 2026
13F holders
1,161
13D/G owners
3
CIK / CUSIP context first
Open Q2 2026 holders
IRM full holder history
IRON MOUNTAIN INC SEC filings
IRON MOUNTAIN INC company facts
IRON MOUNTAIN INC insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 46284V101:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
3
Security
IRM
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC | 8.4% | $2,558,722,929 | 25,051,135 | Vanguard Portfolio Management | 31 Mar 2026 | |||
| VANGUARD CAPITAL MANAGEMENT LLC | 7.4% | $2,234,037,028 | 21,872,303 | Vanguard Capital Management | 31 Mar 2026 | |||
| COHEN & STEERS, INC. | 4.9% | -26% | $1,503,596,476 | -$470,109,106 | 14,555,629 | -24% | Cohen & Steers, Inc. | 30 Apr 2026 |
As of 30 Jun 2026, 1,161 institutional investors reported holding 256,148,405 shares of IRON MOUNTAIN INC - Common Stock (IRM). This represents 86% of the company’s total 297,661,125 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
61%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| BlackRock, Inc. | 11% | 33,570,910 | +1.7% | 0.06% | $4,240,341,746 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 8.6% | 25,568,944 | +2.2% | 0.15% | $3,229,613,316 |
| VANGUARD CAPITAL MANAGEMENT LLC | 6.4% | 18,953,705 | +1% | 0.05% | $2,394,042,478 |
| STATE STREET CORP | 5.9% | 17,634,044 | +0.47% | 0.07% | $2,242,115,113 |
| COHEN & STEERS, INC. | 4% | 12,019,735 | -26% | 2.4% | $1,518,214,000 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.9% | 8,649,249 | +1.9% | 0.06% | $1,088,492,024 |
| FMR LLC | 2.6% | 7,872,365 | +5.2% | 0.04% | $994,358,385 |
| DIMENSIONAL FUND ADVISORS LP | 1.6% | 4,625,684 | +1.6% | 0.11% | $584,312,010 |
| MORGAN STANLEY | 1.5% | 4,426,922 | -4.8% | 0.03% | $559,164,617 |
| PRINCIPAL FINANCIAL GROUP INC | 1.5% | 4,373,424 | -4.2% | 0.27% | $552,399,724 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 1.4% | 4,263,487 | +6.2% | 0.07% | $538,521,043 |
| NORTHERN TRUST CORP | 1.4% | 4,222,967 | +1.7% | 0.06% | $533,402,961 |
| NORGES BANK | 1.4% | 4,214,697 | 0.05% | $532,358,378 | |
| Invesco Ltd. | 1.4% | 4,065,649 | +3.7% | 0.04% | $513,532,150 |
| Legal & General Group Plc | 1.1% | 3,244,741 | +3.5% | 0.09% | $409,843,245 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 1.1% | 3,193,560 | +29674% | 0.07% | $403,378,564 |
| DEUTSCHE BANK AG\ | 1% | 3,049,079 | -1.4% | 0.11% | $385,129,168 |
| GOLDMAN SACHS GROUP INC | 0.95% | 2,822,732 | +27% | 0.04% | $356,539,232 |
| CENTERSQUARE INVESTMENT MANAGEMENT LLC | 0.78% | 2,323,974 | +0.6% | 2.5% | $293,541,156 |
| Nuveen, LLC | 0.75% | 2,218,771 | +7.3% | 0.07% | $280,252,866 |
| JPMORGAN CHASE & CO | 0.74% | 2,212,137 | +4.2% | 0.02% | $287,511,706 |
| AQR CAPITAL MANAGEMENT LLC | 0.71% | 2,127,095 | +15% | 0.09% | $266,503,747 |
| PRUDENTIAL FINANCIAL INC | 0.66% | 1,974,079 | -18% | 0.27% | $249,345,919 |
| Vontobel Holding Ltd. | 0.64% | 1,919,656 | -9.3% | 0.81% | $242,471,749 |
| Daiwa Securities Group Inc. | 0.63% | 1,861,547 | -40% | 0.53% | $235,132,001 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
50
Latest
Q2 2026
Rows shown
1-25 of 50
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 256,148,405 | $32,321,498,331 | +$492,521,445 | $126.31 | 1,161 |
| 2026 Q1 | 252,804,353 | $25,805,946,586 | -$295,803,316 | $102.14 | 1,086 |
| 2025 Q4 | 257,162,908 | $21,344,532,604 | +$502,933,470 | $82.95 | 1,003 |
| 2025 Q3 | 250,099,173 | $25,501,731,178 | +$119,529,096 | $101.94 | 1,008 |
| 2025 Q2 | 248,525,285 | $25,494,373,784 | +$803,176,666 | $102.57 | 1,032 |
| 2025 Q1 | 240,934,690 | $20,734,604,323 | +$263,720,115 | $86.04 | 981 |
| 2024 Q4 | 236,810,872 | $24,896,739,978 | -$607,469,785 | $105.11 | 1,052 |
| 2024 Q3 | 241,814,752 | $28,741,204,354 | -$1,107,026,346 | $118.83 | 1,044 |
| 2024 Q2 | 247,404,957 | $22,194,271,901 | +$1,038,973,385 | $89.62 | 958 |
| 2024 Q1 | 236,401,763 | $18,948,590,587 | +$213,667,716 | $80.21 | 929 |
| 2023 Q4 | 233,491,997 | $16,340,519,763 | +$271,706,582 | $69.98 | 884 |
| 2023 Q3 | 229,526,142 | $13,658,760,340 | +$171,582,469 | $59.45 | 826 |
| 2023 Q2 | 226,655,213 | $12,884,186,843 | +$83,715,858 | $56.82 | 805 |
| 2023 Q1 | 224,502,203 | $11,873,411,821 | -$142,387,662 | $52.91 | 778 |
| 2022 Q4 | 227,868,373 | $11,377,567,891 | +$44,555,254 | $49.85 | 773 |
| 2022 Q3 | 226,777,832 | $9,985,042,681 | +$96,567,031 | $43.97 | 731 |
| 2022 Q2 | 224,032,661 | $10,915,712,274 | -$16,300,595 | $48.69 | 755 |
| 2022 Q1 | 224,442,000 | $12,439,113,556 | -$172,066,245 | $55.41 | 765 |
| 2021 Q4 | 227,876,068 | $11,926,247,380 | -$32,879,189 | $52.33 | 735 |
| 2021 Q3 | 228,189,194 | $9,924,915,322 | -$6,524,012 | $43.45 | 693 |
| 2021 Q2 | 228,564,720 | $9,682,737,503 | +$46,970,021 | $42.32 | 674 |
| 2021 Q1 | 227,132,792 | $8,414,631,609 | -$145,818,371 | $37.01 | 611 |
| 2020 Q4 | 231,708,448 | $6,837,063,849 | -$283,592,825 | $29.48 | 591 |
| 2020 Q3 | 242,359,753 | $6,501,463,965 | -$98,472,508 | $26.79 | 576 |
| 2020 Q2 | 245,858,050 | $6,425,333,738 | +$15,126,586 | $26.10 | 547 |