- Type / Class
- Equity / Common Stock
- Shares outstanding
- 297,661,125
- Total 13F shares
- 155,835,570
- Share change
- -3,558,188
- Total reported value
- $15,905,784,230
- Put/Call ratio
- 312%
- Price per share
- $102.14
- Number of holders
- 801
- Value change
- -$270,544,253
- Number of buys
- 401
- Number of sells
- 299
Quarterly Holders Quick Answers
What is CUSIP 46284V101?
CUSIP 46284V101 identifies IRM - IRON MOUNTAIN INC - Common Stock in SEC institutional holdings data.
Need full ownership history?
Open the full security ownership history page.
Next holder-history checks
These links keep the next click tied to holder verification, nearby quarters, or outside-13F ownership context.
- Back to full security ownership history for the broader multi-quarter picture.
- Latest 13F filings for newly reported positions across managers.
- Latest Schedule 13D/13G reports for ownership changes outside the 13F cadence.
- SEC investors directory for manager drilldown.
Explore More Reporting Periods
Jump to adjacent filing periods for faster comparison and easier crawl discovery.
- Previous quarter: Q4 2025
Recent filing periods for CUSIP 46284V101:
Top shareholders of IRM - IRON MOUNTAIN INC - Common Stock (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| VANGUARD GROUP INC |
13F
|
Company |
16%
|
46,627,483
|
$3,867,749,715 | — | 31 Dec 2025 | |
| BlackRock, Inc. |
13F
|
Company |
11%
|
32,919,658
|
$2,730,685,613 | — | 31 Dec 2025 | |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
|
Vanguard Portfolio Management |
8.4%
|
25,051,135
|
$2,558,722,929 | $0 | 31 Mar 2026 | |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
|
Vanguard Capital Management |
7.4%
|
21,872,303
|
$2,234,037,028 | $0 | 31 Mar 2026 | |
| COHEN & STEERS, INC. |
13F
|
Company |
6.4%
|
18,903,716
|
$1,568,110,000 | — | 31 Dec 2025 | |
| STATE STREET CORP |
13F
|
Company |
5.7%
|
16,888,798
|
$1,415,001,718 | — | 31 Dec 2025 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
2.8%
|
8,292,653
|
$685,374,233 | — | 31 Dec 2025 | |
| FMR LLC |
13F
|
Company |
2.7%
|
7,984,304
|
$662,298,027 | — | 31 Dec 2025 | |
| NORGES BANK |
13F
|
Company |
1.5%
|
4,447,133
|
$368,889,682 | — | 31 Dec 2025 | |
| DIMENSIONAL FUND ADVISORS LP |
13F
|
Company |
1.5%
|
4,429,359
|
$367,418,097 | — | 31 Dec 2025 | |
| Invesco Ltd. |
13F
|
Company |
1.5%
|
4,417,367
|
$366,420,630 | — | 31 Dec 2025 | |
| PRINCIPAL FINANCIAL GROUP INC |
13F
|
Company |
1.4%
|
4,207,596
|
$349,020,857 | — | 31 Dec 2025 | |
| NORTHERN TRUST CORP |
13F
|
Company |
1.4%
|
4,152,569
|
$344,455,599 | — | 31 Dec 2025 | |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC |
13F
|
Company |
1.3%
|
3,880,275
|
$321,868,811 | — | 31 Dec 2025 | |
| Daiwa Securities Group Inc. |
13F
|
Company |
1.2%
|
3,654,086
|
$303,106,000 | — | 31 Dec 2025 | |
| MORGAN STANLEY |
13F
|
Company |
1.2%
|
3,598,973
|
$298,534,997 | — | 31 Dec 2025 | |
| Legal & General Group Plc |
13F
|
Company |
1.1%
|
3,356,420
|
$278,415,040 | — | 31 Dec 2025 | |
| Contour Asset Management LLC |
13F
|
Company |
0.95%
|
2,832,182
|
$234,929,497 | — | 31 Dec 2025 | |
| CENTERSQUARE INVESTMENT MANAGEMENT LLC |
13F
|
Company |
0.88%
|
2,631,453
|
$218,279,027 | — | 31 Dec 2025 | |
| DEUTSCHE BANK AG\ |
13F
|
Company |
0.85%
|
2,541,992
|
$210,858,237 | — | 31 Dec 2025 | |
| PRUDENTIAL FINANCIAL INC |
13F
|
Company |
0.78%
|
2,310,481
|
$191,654,398 | — | 31 Dec 2025 | |
| Pictet Asset Management Holding SA |
13F
|
Company |
0.77%
|
2,295,965
|
$190,433,581 | — | 31 Dec 2025 | |
| Nuveen, LLC |
13F
|
Company |
0.71%
|
2,127,931
|
$176,511,876 | — | 31 Dec 2025 | |
| Capital World Investors |
13F
|
Company |
0.71%
|
2,117,169
|
$175,619,169 | — | 31 Dec 2025 | |
| JPMORGAN CHASE & CO |
13F
|
Company |
0.65%
|
1,927,935
|
$159,922,241 | — | 31 Dec 2025 | |
| AMERIPRISE FINANCIAL INC |
13F
|
Company |
0.59%
|
1,744,405
|
$142,472,791 | — | 31 Dec 2025 | |
| Vontobel Holding Ltd. |
13F
|
Company |
0.57%
|
1,689,246
|
$140,122,956 | — | 31 Dec 2025 | |
| Bank of New York Mellon Corp |
13F
|
Company |
0.57%
|
1,685,978
|
$139,851,870 | — | 31 Dec 2025 | |
| PGGM Investments |
13F
|
Individual |
0.56%
|
1,657,159
|
$137,461,000 | — | 31 Dec 2025 | |
| DUFF & PHELPS INVESTMENT MANAGEMENT CO |
13F
|
Company |
0.53%
|
1,580,452
|
$131,098,493 | — | 31 Dec 2025 | |
| GOLDMAN SACHS GROUP INC |
13F
|
Company |
0.51%
|
1,525,240
|
$126,518,662 | — | 31 Dec 2025 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
0.51%
|
1,510,345
|
$125,283,103 | — | 31 Dec 2025 | |
| CBRE INVESTMENT MANAGEMENT LISTED REAL ASSETS LLC |
13F
|
Company |
0.49%
|
1,446,597
|
$119,995,221 | — | 31 Dec 2025 | |
| Russell Investments Group, Ltd. |
13F
|
Company |
0.47%
|
1,405,760
|
$116,627,186 | — | 31 Dec 2025 | |
| Amundi |
13F
|
Individual |
0.45%
|
1,333,693
|
$110,629,834 | — | 31 Dec 2025 | |
| ROYAL BANK OF CANADA |
13F
|
Company |
0.43%
|
1,285,871
|
$106,663,000 | — | 31 Dec 2025 | |
| Deutsche Girozentrale DekaBank |
13F
|
Individual |
0.38%
|
1,122,500
|
$95,828,000 | — | 31 Dec 2025 | |
| CITADEL ADVISORS LLC |
13F
|
Company |
0.38%
|
1,119,371
|
$92,851,824 | — | 31 Dec 2025 | |
| HSBC HOLDINGS PLC |
13F
|
Company |
0.35%
|
1,055,775
|
$87,577,061 | — | 31 Dec 2025 | |
| SEI INVESTMENTS CO |
13F
|
Company |
0.34%
|
1,024,664
|
$84,995,814 | — | 31 Dec 2025 | |
| AQR CAPITAL MANAGEMENT LLC |
13F
|
Company |
0.31%
|
923,196
|
$76,579,076 | — | 31 Dec 2025 | |
| Sumitomo Mitsui Trust Group, Inc. |
13F
|
Company |
0.3%
|
906,888
|
$75,226,360 | — | 31 Dec 2025 | |
| Mitsubishi UFJ Asset Management Co., Ltd. |
13F
|
Company |
0.28%
|
839,566
|
$69,885,474 | — | 31 Dec 2025 | |
| Swiss National Bank |
13F
|
Company |
0.27%
|
809,261
|
$67,128,200 | — | 31 Dec 2025 | |
| UBS Group AG |
13F
|
Company |
0.27%
|
795,908
|
$66,020,568 | — | 31 Dec 2025 | |
| Point72 Asset Management, L.P. |
13F
|
Company |
0.27%
|
790,504
|
$65,572,307 | — | 31 Dec 2025 | |
| BARCLAYS PLC |
13F
|
Company |
0.24%
|
728,857
|
$60,458,688 | — | 31 Dec 2025 | |
| CIBC Private Wealth Group LLC |
13F
|
Company |
0.23%
|
677,651
|
$56,211,138 | — | 31 Dec 2025 | |
| ADAGE CAPITAL PARTNERS GP, L.L.C. |
13F
|
Company |
0.22%
|
656,852
|
$54,485,873 | — | 31 Dec 2025 | |
| WELCH & FORBES LLC |
13F
|
Company |
0.22%
|
656,364
|
$54,445,372 | — | 31 Dec 2025 |
Institutional Holders of IRON MOUNTAIN INC - Common Stock (IRM) as of Q1 2026
As of 31 Mar 2026,
IRON MOUNTAIN INC - Common Stock (IRM) was held by
801 institutional
shareholders
that filed Form 13F with the SEC.
Together, they reported ownership of
155,835,570 shares.
The largest 10 holders included
BlackRock, Inc., VANGUARD PORTFOLIO MANAGEMENT LLC, VANGUARD CAPITAL MANAGEMENT LLC, PRINCIPAL FINANCIAL GROUP INC, DIMENSIONAL FUND ADVISORS LP, Invesco Ltd., Legal & General Group Plc, Daiwa Securities Group Inc., DEUTSCHE BANK AG\, and PRUDENTIAL FINANCIAL INC.
This page lists
801
institutional shareholders reporting positions in this security
for the Q1 2026 filing period.
| Investor | Option | Weight % | Change % | Value $ | * Price | Shares | Share Change | Activity | Report Period |
|---|
Compare Q1 2026 vs Q4 2025 Across Filers
Q4 2025 holders
998
Q1 2026 holders
801
Holder diff
-197
| Investor | Q4 2025 Shares | Q1 2026 Shares | Share Diff | Share Chg % | Q4 2025 Value $ | Q1 2026 Value $ | Value Diff $ | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend
* Reported Price is the price of the security as of the portfolio date. This value is significant in that it is the last known price at which the security was still held.
An asterisk sign (*) next to the price indicates that the price is likely invalid.
An asterisk sign (*) next to the price indicates that the price is likely invalid.