IRM Iron Mountain Incorporated
Iron Mountain Incorporated (IRM) Institutional Ownership
What the institutions did with IRM last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.
Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.
Sign in or subscribeLargest holders
| Manager | Shares | % of reported |
|---|---|---|
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 54.9M | 17.6% |
| BlackRock, Inc. | 33.6M | 10.8% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 25.6M | 8.2% |
| VANGUARD CAPITAL MANAGEMENT LLC | 19.0M | 6.1% |
| STATE STREET CORP | 17.6M | 5.7% |
| COHEN & STEERS, INC. | 12.0M | 3.9% |
| GEODE CAPITAL MANAGEMENT, LLC | 8.6M | 2.8% |
| FMR LLC | 7.9M | 2.5% |
| DIMENSIONAL FUND ADVISORS LP | 4.6M | 1.5% |
| MORGAN STANLEY | 4.4M | 1.4% |
| PRINCIPAL FINANCIAL GROUP INC | 4.4M | 1.4% |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 4.3M | 1.4% |
| NORTHERN TRUST CORP | 4.2M | 1.4% |
| NORGES BANK | 4.2M | 1.4% |
| Invesco Ltd. | 4.1M | 1.3% |
| Legal & General Group Plc | 3.2M | 1.0% |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 3.2M | 1.0% |
| DEUTSCHE BANK AG\ | 3.0M | 1.0% |
| GOLDMAN SACHS GROUP INC | 2.8M | 0.9% |
| CENTERSQUARE INVESTMENT MANAGEMENT LLC | 2.3M | 0.7% |
| Nuveen, LLC | 2.2M | 0.7% |
| JPMORGAN CHASE & CO | 2.2M | 0.7% |
| AQR CAPITAL MANAGEMENT LLC | 2.1M | 0.7% |
| PRUDENTIAL FINANCIAL INC | 2.0M | 0.6% |
| Vontobel Holding Ltd. | 1.9M | 0.6% |
Largest changes
| Manager | Action | Previous | Current | Change |
|---|---|---|---|---|
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | Increased | 422.9K | 54.9M | +54.5M |
| COHEN & STEERS, INC. | Reduced | 16.2M | 12.0M | -4.1M |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Increased | 10.7K | 3.2M | +3.2M |
| Daiwa Securities Group Inc. | Reduced | 3.1M | 1.9M | -1.2M |
| PGGM Investments | Reduced | 1.4M | 675.1K | -694.9K |
| Capital World Investors | Reduced | 1.9M | 1.2M | -650.0K |
| Epoch Investment Partners, Inc. | Sold Out | 616.5K | 0 | -616.5K |
| GOLDMAN SACHS GROUP INC | Increased | 2.2M | 2.8M | +606.1K |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Increased | 25.0M | 25.6M | +553.4K |
| BlackRock, Inc. | Increased | 33.0M | 33.6M | +549.6K |
| PRUDENTIAL FINANCIAL INC | Reduced | 2.4M | 2.0M | -442.0K |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | New | 0 | 412.7K | +412.7K |
| FMR LLC | Increased | 7.5M | 7.9M | +388.0K |
| AMERICAN CENTURY COMPANIES INC | Increased | 815.8K | 1.2M | +338.7K |
| Aberdeen Group plc | Increased | 371.2K | 691.5K | +320.3K |
| JANE STREET GROUP, LLC | Reduced | 707.4K | 396.5K | -310.9K |
| STRS OHIO | Sold Out | 287.8K | 0 | -287.8K |
| SG Americas Securities, LLC | New | 0 | 284.6K | +284.6K |
| Robeco Institutional Asset Management B.V. | Increased | 14.6K | 297.9K | +283.3K |
| AQR CAPITAL MANAGEMENT LLC | Increased | 1.8M | 2.1M | +281.0K |
| BANK OF AMERICA CORP /DE/ | Reduced | 1.4M | 1.1M | -280.5K |
| SEI INVESTMENTS CO | Reduced | 974.8K | 697.7K | -277.1K |
| Quantinno Capital Management LP | Increased | 322.0K | 590.6K | +268.6K |
| RAYMOND JAMES FINANCIAL INC | Increased | 295.1K | 561.5K | +266.4K |
| Point72 Asset Management, L.P. | Reduced | 377.6K | 123.3K | -254.4K |
13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.