IRM Iron Mountain Incorporated

NYSE
$115.18

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.

Managers compared
1,214
filed both this quarter and last
Managers holding
1,153
+77 on the quarter
Buyers
585
138 opened new
Sellers
442
61 sold out entirely
Buyer share
57.0%
of managers who traded it
Breadth
+13.9
net buyers, as a share of those trading

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.

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Ownership map

Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.

Cut Unchanged Added Color saturates at ±50%.

Largest holders

Manager Shares % of reported
BlackRock, Inc. 33.6M 13.1%
VANGUARD PORTFOLIO MANAGEMENT LLC 25.6M 9.9%
VANGUARD CAPITAL MANAGEMENT LLC 19.0M 7.4%
STATE STREET CORP 17.6M 6.9%
COHEN & STEERS, INC. 12.0M 4.7%
GEODE CAPITAL MANAGEMENT, LLC 8.6M 3.4%
FMR LLC 7.9M 3.1%
DIMENSIONAL FUND ADVISORS LP 4.6M 1.8%
MORGAN STANLEY 4.4M 1.7%
PRINCIPAL FINANCIAL GROUP INC 4.4M 1.7%
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 4.3M 1.7%
NORTHERN TRUST CORP 4.2M 1.6%
NORGES BANK 4.2M 1.6%
Invesco Ltd. 4.1M 1.6%
Legal & General Group Plc 3.2M 1.3%
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 3.2M 1.2%
DEUTSCHE BANK AG\ 3.0M 1.2%
GOLDMAN SACHS GROUP INC 2.8M 1.1%
CENTERSQUARE INVESTMENT MANAGEMENT LLC 2.3M 0.9%
Nuveen, LLC 2.2M 0.9%
JPMORGAN CHASE & CO 2.2M 0.9%
AQR CAPITAL MANAGEMENT LLC 2.1M 0.8%
PRUDENTIAL FINANCIAL INC 2.0M 0.8%
Vontobel Holding Ltd. 1.9M 0.7%
Daiwa Securities Group Inc. 1.9M 0.7%

Largest changes

Manager Action Previous Current Change
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
CHARLES SCHWAB INVESTMENT MANAGEMENT INC Increased 4.0M 4.3M +250.5K
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC New 0 235.6K +235.6K
ROYAL BANK OF CANADA Increased 1.4M 1.6M +229.8K
HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND Increased 214.9K 443.9K +229.0K
MORGAN STANLEY Reduced 4.7M 4.4M -225.3K
MILLENNIUM MANAGEMENT LLC Reduced 374.5K 157.1K -217.4K
BAMCO INC /NY/ Reduced 525.3K 310.7K -214.5K
Schonfeld Strategic Advisors LLC Reduced 248.9K 39.4K -209.4K
Vontobel Holding Ltd. Reduced 2.1M 1.9M -197.2K
GW&K Investment Management, LLC Increased 244 196.3K +196.0K
Border to Coast Pensions Partnership Ltd Reduced 470.0K 275.0K -195.0K
VANGUARD CAPITAL MANAGEMENT LLC Increased 18.8M 19.0M +194.8K
PRINCIPAL FINANCIAL GROUP INC Reduced 4.6M 4.4M -192.7K
Hudson Bay Capital Management LP Sold Out 190.9K 0 -190.9K
BROOKFIELD Corp /ON/ Reduced 188.3K 5.3K -183.0K
AMERIPRISE FINANCIAL INC Reduced 1.9M 1.7M -182.7K
Contour Asset Management LLC Reduced 1.4M 1.3M -170.1K
CBRE INVESTMENT MANAGEMENT LISTED REAL ASSETS LLC Reduced 1.2M 1.1M -165.0K
WELLINGTON MANAGEMENT GROUP LLP Increased 347.9K 512.9K +165.0K
SG Capital Management LLC Sold Out 163.6K 0 -163.6K
GEODE CAPITAL MANAGEMENT, LLC Increased 8.5M 8.6M +163.1K
Nuveen, LLC Increased 2.1M 2.2M +150.4K
Invesco Ltd. Increased 3.9M 4.1M +144.1K
BNP PARIBAS FINANCIAL MARKETS Increased 508.5K 648.2K +139.7K
Gillson Capital LP New 0 137.9K +137.9K
Ensign Peak Advisors, Inc Reduced 297.3K 163.8K -133.5K
NATIXIS Increased 8.1K 138.3K +130.2K
ACADIAN ASSET MANAGEMENT LLC Increased 168.9K 292.1K +123.2K
Balyasny Asset Management L.P. Reduced 128.7K 6.7K -121.9K
DUFF & PHELPS INVESTMENT MANAGEMENT CO Reduced 1.6M 1.5M -119.9K
PUBLIC EMPLOYEES RETIREMENT ASSOCIATION OF COLORADO Increased 28.3K 144.6K +116.2K
Cambridge Investment Research Advisors, Inc. Increased 124.2K 240.4K +116.2K
UBS Group AG Increased 801.4K 915.1K +113.7K
TWO SIGMA INVESTMENTS, LP Reduced 179.2K 65.9K -113.3K
O'Neil Global Advisors, Inc. New 0 113.2K +113.2K
INTECH INVESTMENT MANAGEMENT LLC Increased 22.3K 133.0K +110.7K

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.