IRM Institutional Ownership & Shareholders
IRON MOUNTAIN INC (IRM) is currently held by 1,152 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $30.94B based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of IRM tracked by InsiderSet, reporting ownership valued at approximately $4.24B in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $3.87B, representing an estimated loss of -8.81% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 56% of the total disclosed IRM value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Vanguard Portfolio Management Llc, Vanguard Capital Management Llc, and several other long-term asset managers with concentrated positions in IRON MOUNTAIN INC (IRM).
This page ranks the largest institutional IRM shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
1,152
Total Reported Value
$30.94B
Largest Holder
Blackrock, Inc.
Largest Position
$4.24B
Insider Transactions (90d)
20
Latest Filing Quarter
Q2 2026
New Institutional Positions
37
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.06% | 33,570,910 | $4,240,341,746 | $3,866,697,414 | -$373,644,332 | -8.81% | |
| Vanguard Portfolio Management Llc | 0.15% | 25,568,944 | $3,229,613,316 | $2,945,030,970 | -$284,582,346 | -8.81% | |
| Vanguard Capital Management Llc | 0.05% | 18,953,705 | $2,394,042,478 | $2,183,087,742 | -$210,954,736 | -8.81% | |
| State Street Corp | 0.07% | 17,634,044 | $2,242,115,113 | $2,031,089,188 | -$211,025,925 | -9.41% | |
| Cohen & Steers, Inc. | 2.40% | 12,019,735 | $1,518,214,000 | $1,384,433,077 | -$133,780,923 | -8.81% | |
| Geode Capital Management, Llc | 0.06% | 8,649,249 | $1,088,492,024 | $996,220,500 | -$92,271,524 | -8.48% | |
| Fmr Llc | 0.04% | 7,872,365 | $994,358,385 | $906,739,001 | -$87,619,384 | -8.81% | |
| Dimensional Fund Advisors Lp | 0.11% | 4,625,684 | $584,312,010 | $532,786,283 | -$51,525,727 | -8.82% | |
| Morgan Stanley | 0.03% | 4,426,922 | $559,164,617 | $509,892,876 | -$49,271,741 | -8.81% | |
| Charles Schwab Investment Management Inc | 0.07% | 4,263,487 | $538,521,043 | $491,068,433 | -$47,452,610 | -8.81% | |
| Northern Trust Corp | 0.06% | 4,222,967 | $533,402,961 | $486,401,339 | -$47,001,622 | -8.81% | |
| Norges Bank | 0.05% | 4,214,697 | $532,358,378 | $485,448,800 | -$46,909,578 | -8.81% | |
| Invesco Ltd. | 0.04% | 4,065,649 | $513,532,150 | $468,281,452 | -$45,250,698 | -8.81% | |
| Legal & General Group Plc | 0.09% | 3,244,741 | $409,843,245 | $373,729,268 | -$36,113,977 | -8.81% | |
| Deutsche Bank Ag\ | 0.11% | 3,049,079 | $385,129,168 | $351,192,919 | -$33,936,249 | -8.81% | |
| Goldman Sachs Group Inc | 0.04% | 2,822,732 | $356,539,232 | $325,122,272 | -$31,416,960 | -8.81% | |
| Principal Financial Group Inc | 0.16% | 2,880,424 | $319,584,789 | $331,767,236 | +$12,182,447 | +3.81% | |
| Centersquare Investment Management Llc | 2.51% | 2,323,974 | $293,541,156 | $267,675,325 | -$25,865,831 | -8.81% | |
| Jpmorgan Chase & Co | 0.02% | 2,212,137 | $287,511,706 | $254,793,940 | -$32,717,766 | -11.38% | |
| Nuveen, Llc | 0.07% | 2,218,771 | $280,252,866 | $255,558,044 | -$24,694,822 | -8.81% | |
| Aqr Capital Management Llc | 0.09% | 2,127,095 | $266,503,747 | $244,998,802 | -$21,504,945 | -8.07% | |
| Prudential Financial Inc | 0.27% | 1,974,079 | $249,345,919 | $227,374,419 | -$21,971,500 | -8.81% | |
| Daiwa Securities Group Inc. | 0.48% | 1,941,681 | $215,429,507 | $223,642,818 | +$8,213,311 | +3.81% | |
| Ameriprise Financial Inc | 0.04% | 1,668,337 | $210,902,234 | $192,159,056 | -$18,743,178 | -8.89% | |
| Vanguard Fiduciary Trust Co | 0.05% | 1,658,635 | $209,502,187 | $191,041,579 | -$18,460,608 | -8.81% | |
| Royal Bank Of Canada | 0.04% | 1,640,511 | $207,212,000 | $188,954,057 | -$18,257,943 | -8.81% | |
| Bank Of New York Mellon Corp | 0.03% | 1,600,078 | $202,105,893 | $184,296,984 | -$17,808,909 | -8.81% | |
| Duff & Phelps Investment Management Co | 1.73% | 1,455,435 | $183,835,995 | $167,637,003 | -$16,198,992 | -8.81% | |
| Russell Investments Group, Ltd. | 0.16% | 1,403,623 | $177,422,830 | $161,669,297 | -$15,753,533 | -8.88% | |
| Hsbc Holdings Plc | 0.08% | 1,347,871 | $170,307,229 | $155,247,782 | -$15,059,447 | -8.84% | |
| Contour Asset Management Llc | 3.81% | 1,274,684 | $161,005,336 | $146,818,103 | -$14,187,233 | -8.81% | |
| Capital World Investors | 0.02% | 1,217,169 | $153,740,616 | $140,193,525 | -$13,547,091 | -8.81% | |
| American Century Companies Inc | 0.06% | 1,154,487 | $145,823,458 | $132,973,813 | -$12,849,645 | -8.81% | |
| Bank Of America Corp | 0.01% | 1,118,827 | $141,319,031 | $128,866,494 | -$12,452,537 | -8.81% | |
| Cbre Investment Management Listed Real Assets Llc | 1.89% | 1,072,881 | $135,515,599 | $123,574,434 | -$11,941,165 | -8.81% | |
| Mitsubishi Ufj Asset Management Co., Ltd. | 0.07% | 982,596 | $124,111,701 | $113,175,407 | -$10,936,294 | -8.81% | |
| Pictet Asset Management Holding Sa | 0.11% | 1,080,998 | $119,951,283 | $124,509,350 | +$4,558,067 | +3.80% | |
| Ubs Group Ag | 0.02% | 915,101 | $115,586,407 | $105,401,333 | -$10,185,074 | -8.81% | |
| Swiss National Bank | 0.06% | 839,061 | $105,981,795 | $96,643,046 | -$9,338,749 | -8.81% | |
| Cibc Bancorp Usa Inc. | 0.12% | 777,480 | $98,243,686 | $89,550,146 | -$8,693,540 | -8.85% | |
| Sumitomo Mitsui Trust Group, Inc. | 0.05% | 847,704 | $94,052,759 | $97,638,547 | +$3,585,788 | +3.81% | |
| Barclays Plc | 0.03% | 743,343 | $93,891,653 | $85,618,247 | -$8,273,406 | -8.81% | |
| Sei Investments Co | 0.08% | 697,737 | $88,131,437 | $80,365,348 | -$7,766,089 | -8.81% | |
| Aberdeen Group Plc | 0.12% | 691,514 | $87,345,133 | $79,648,583 | -$7,696,550 | -8.81% | |
| Apg Asset Management Us Inc. | 0.60% | 703,912 | $85,806,873 | $81,076,584 | -$4,730,289 | -5.51% | |
| Pggm Investments | 2.10% | 675,093 | $85,271,000 | $77,757,212 | -$7,513,788 | -8.81% | |
| Wells Fargo & Company/Mn | 0.01% | 662,157 | $83,637,061 | $76,267,243 | -$7,369,818 | -8.81% | |
| Bnp Paribas Financial Markets | 0.04% | 648,227 | $81,877,553 | $74,662,786 | -$7,214,767 | -8.81% | |
| Vanguard Global Advisers, Llc | 0.04% | 641,901 | $81,078,515 | $73,934,157 | -$7,144,358 | -8.81% | |
| Lpl Financial Llc | 0.02% | 640,383 | $80,886,883 | $73,759,314 | -$7,127,569 | -8.81% |
Frequently asked questions about IRM
Who are the largest institutional holders of IRM?
The largest institutional holders of IRM reported in the latest SEC Form 13F filings include Blackrock, Inc., Vanguard Portfolio Management Llc, Vanguard Capital Management Llc, State Street Corp, and Cohen & Steers, Inc.. InsiderSet ranks institutional holders by their latest reported IRM position.
What is IRM institutional ownership?
This page tracks IRM positions reported by institutional investment managers through SEC Form 13F. IRON MOUNTAIN INC (IRM) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own IRM?
InsiderSet currently tracks 1,152 institutional managers reporting IRM holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of IRM shareholders.
How much IRM stock do institutions own?
Institutional investment managers disclosed approximately $30.94B in IRM holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was IRM institutional ownership last updated?
The latest IRM institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional IRM holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its IRM position after the reporting date.
Are institutions buying or selling IRM?
Institutional buying and selling can be analyzed by comparing IRM positions across consecutive 13F reporting periods. InsiderSet's IRM Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View IRM ownership changes.
How has IRM institutional ownership changed over time?
InsiderSet tracks IRM institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.